Exposure apparatus and device manufacturing method

ABSTRACT

Positional information of each of wafer stages during exposure and during alignment is measured directly under a projection optical system and directly under a primary alignment system, respectively, by a plurality of encoder heads, Z heads and the like, which a measurement bar placed below surface plates has, using gratings placed on the lower surfaces of fine movement stages. Consequently, high-precision measurement of the positional information of the wafer stages can be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims the benefit of ProvisionalApplication No. 61/218,450 filed Jun. 19, 2009, the disclosure of whichis hereby incorporated herein by reference in its entirety.

BACKGROUND OF TEE INVENTION

1. Field of the Invention

The present, invention relates to exposure apparatuses and devicemanufacturing methods, and more particularly to an exposure apparatusthat exposes an object with an energy beam via an optical system, and adevice manufacturing method that uses the exposure apparatus.

2. Description of the Background Art

Conventionally, in a lithography process for manufacturing electrondevices (microdevices) such as semiconductor devices (integratedcircuits or the like) or liquid crystal display elements, an exposureapparatus such as a projection exposure apparatus by a step-and-repeatmethod (a so-called stepper), or a projection exposure apparatus by astep-and-scan method (a so-called scanning stepper (which is also calleda scanner)) is mainly used. This type of the projection exposureapparatus has a stage device that holds a substrate such as a wafer or aglass plate (hereinafter, generically referred to as a wafer) and drivesthe wafer along a predetermined two-dimensional plane.

In order to perform high-precision exposure, the high-precisionpositional controllability of a stage is required for the stage device,and in order to improve throughput of the exposure operation, higherspeed and higher acceleration of the stage are also required. To copewith these requirements, in recent years, a stage device that controlsthe position of a wafer within a two-dimensional plane using a planarmotor by an electromagnetic force drive method has been developed (e.g.refer to U.S. Pat. No. 6,437,463).

Further, for example, the fifth embodiment of U.S. Patent ApplicationPublication No 2008/0094594 discloses the exposure apparatus in which anencoder head is placed within a recessed section formed on the uppersurface of a surface plate. In the exposure apparatus described in U.S.Patent Application Publication No. 2008/0094594, positional informationof the wafer stage is measured with high precision by causingmeasurement beams to be incident on a two-dimensional grating placed onthe wafer stage from directly below.

However, if the planar motor in which the wafer stage has the mover andthe surface plate has the stator as disclosed in U.S. Pat. No. 6,437,463is applied to the exposure apparatus in which the encoder head is placedinside the surface plate as disclosed in the fifth embodiment of U.S.Patent Application Publication No. 2008/0094594, there is a possibilitythat the measurement accuracy of the encoder system is degraded owing toa reaction force acting on the surface plate when the wafer stage isdriven.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda first exposure apparatus that exposes an object with an energy beamvia an optical system supported by a first support member, the apparatuscomprising: a movable body that holds the object and is movable along apredetermined two-dimensional plane; a guide surface forming member thatforms a guide surface used when the movable body moves along thetwo-dimensional plane; a first drive system that drives the movablebody; a second support member that is placed apart from the guidesurface forming member on a side opposite to the optical system, via theguide surface forming member, and is fixed to the first support member;and a measurement system which includes a first measurement member thatirradiates a measurement surface parallel to the two-dimensional planewith a measurement beam and receives light from the measurement surface,and which obtains positional information of the movable body at leastwithin the two-dimensional plane based on an output of the firstmeasurement member, the measurement surface being arranged at one of themovable body and the second support member and at least a part of thefirst measurement member being arranged at the other of the movable bodyand the second support member.

With this apparatus, the measurement system includes the firstmeasurement member at least a part of which is arranged at the other ofthe movable body and the second support member and which irradiates ameasurement beam on the measurement surface arranged on the one of themovable body and the second support member and receives light from themeasurement surface, and the measurement system obtains positionalinformation of the movable body at least within the two-dimensionalplane parallel to the measurement surface based on the output of thefirst measurement member. Further, the second support member on which atleast a part of the first measurement member or the measurement surfaceis arranged is fixed to the first support member that supports theoptical system. Therefore, the influence of fluctuation or the like ofthe surrounding atmosphere of the movable body can be restrained, andthe positional information of the movable body is accurately measured bythe measurement system with the position of the optical system servingas a reference. Furthermore, since the second support member is placedon the side opposite to the optical system via the guide surface formingmember so as to be apart from the guide surface forming member, themeasurement accuracy is not degraded because of a reaction force of thedrive force of the movable body.

In this case, the guide surface is used to guide the movable body in adirection orthogonal to the two-dimensional plane and can be of acontact type or a noncontact type. For example, the guide method of thenoncontact type includes a configuration using static gas bearings suchas air pads, a configuration using magnetic levitation, and the like.Further, the guide surface is not limited to a configuration in whichthe movable body is guided following the shape of the guide surface. Forexample, in the configuration using static gas bearings such as air padsdescribed above, the opposed surface of the guide surface forming memberthat is opposed to the movable body is finished so as to have a highflatness degree and the movable body is guided in a noncontact mannervia a predetermined gap so as to follow the shape of the opposedsurface. On the other hand, in the configuration in which while a partof a motor or the like that uses an electromagnetic force is placed atthe guide surface forming member, a part of the motor or the like isplaced also at the movable body, and a force acting in a directionorthogonal to the two-dimensional plane described above is generated bythe guide surface forming member and the movable body cooperating, theposition of the movable body is controlled by the force on apredetermined two-dimensional plane. For example, a configuration isalso included in which a planar motor is arranged at the guide surfaceforming member and forces in directions which include two directionsorthogonal to each other within the two-dimensional plane and thedirection orthogonal to the two-dimensional plane are made to begenerated on the movable body and the movable body is levitated in anoncontact manner without arranging the static gas bearings describedabove.

According to a second aspect of the present invention, there is provideda second exposure apparatus that exposes an object with an energy beamvia an optical system supported by a first support member, the apparatuscomprising: a movable body that holds the object and is movable along apredetermined two-dimensional plane; a second support member fixed tothe first support member; a first drive system that drives the movablebody; a movable body supporting member placed between the optical systemand the second support member so as to be apart from the second supportmember, which supports the movable body at least at two points of themovable body in a direction orthogonal to a longitudinal direction ofthe second support member when the movable body moves along thetwo-dimensional plane; and a measurement system which includes a firstmeasurement member that irradiates a measurement surface parallel to thetwo-dimensional plane with a measurement beam and receives light fromthe measurement surface, and which obtains positional information of themovable body at least within the two-dimensional plane based on anoutput of the first measurement member, the measurement surface beingarranged at one of the movable body and the second support member and atleast a part of the first measurement member being arranged at the otherof the movable body and the second support member.

With this apparatus, the measurement system includes the firstmeasurement member at least a part of which is arranged at the other ofthe movable body and the second support member and which irradiates ameasurement beam on the measurement surface arranged at the one of themovable body and the second support member and receives light from themeasurement surface, and the measurement system obtains positionalinformation of the movable body at least within the two-dimensionalplane parallel to the measurement surface based on the output of thefirst measurement member. Further, the second support member on which atleast a part of the first measurement member or the measurement surfaceis arranged is fixed to the first support member that supports theoptical system. Therefore, the influence of fluctuation or the like ofthe surrounding atmosphere of the movable body can be restrained, andthe positional information of the movable body is accurately measured bythe measurement system with the position of the optical system servingas a reference. Furthermore, since the second support member is placedon the side opposite to the optical system via the movable bodysupporting member so as to be apart from the movable body supportingmember, the measurement accuracy is not degraded because of a reactionforce of the drive force of the movable body.

In this case, the movable body supporting member supporting the movablebody at least in two points in the direction orthogonal to thelongitudinal direction of the second support member means that themovable body is supported in the direction orthogonal to thelongitudinal direction of the second support member, for example, atonly both ends or at both ends and a mid section in the directionorthogonal to the two-dimensional plane, at a section excluding thecenter and both ends in the direction orthogonal to the longitudinaldirection of the second support member, the entire section includingboth ends in the direction orthogonal to the longitudinal direction ofthe second support member, or the like. In this case, the method of thesupport widely includes the contact support, as a matter of course, andthe noncontact support such as the support via static gas bearings suchas air pads or the magnetic levitation or the like.

According to a third aspect of the present invention, there is provideda device manufacturing method, comprising: exposing an object using oneof the first and second exposure apparatuses of the present invention;and developing the exposed object.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings;

FIG. 1 is a view schematically showing a configuration of an exposureapparatus of an embodiment;

FIG. 2 is a plan view of the exposure apparatus of FIG. 1;

FIG. 3 is a side view of the exposure apparatus of FIG. 1 when viewedfrom the +Y side;

FIG. 4A is a plan view of a wafer stage WST1 which the exposureapparatus is equipped with, FIG. 4B is an end view of the cross sectiontaken along the line B-B of FIG. 4A, and FIG. 4C is an end view of thecross section taken along the line C-C of FIG. 4A;

FIG. 5 is a view showing a configuration of a fine movement stageposition measuring system;

FIG. 6 is a block diagram used to explain input/output relations of amain controller which the exposure apparatus of FIG. 1 is equipped with;

FIG. 7 is a view showing a state where exposure is performed on a wafermounted on wafer stage WST1 and wafer exchange is performed on a waferstage WST2;

FIG. 8 is a view showing a state where exposure is performed on a wafermounted on wafer stage WST1 and wafer alignment is performed to a wafermounted on wafer stage WST2;

FIG. 9 is a view showing a state where wafer stage WST2 moves toward aright-side scrum position on a surface plate 14B;

FIG. 10 is a view showing a state where movement of wafer stage WST1 andwafer stage WST2 to the scrum position is completed;

FIG. 11 is a view showing a state where exposure is performed on a wafermounted on wafer stage WST2 and wafer exchange is performed on waferstage WST1; and

FIG. 12A is a plan view showing a wafer stage related to a modifiedexample, and FIG. 12B is a cross-sectional view taken along the B-B lineof FIG. 12A.

DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present invention is described below, withreference to FIGS. 1 to 11.

FIG. 1 schematically shows a configuration of an exposure apparatus 100related to the embodiment. Exposure apparatus 100 is a projectionexposure apparatus by a step-and-scan method, which is a so-calledscanner. As described later on, a projection optical system PL isprovided in the embodiment, and in the description below, theexplanation is given assuming that a direction parallel to an opticalaxis AX of projection optical system PL is a Z-axis direction, adirection in which a reticle and a wafer are relatively scanned within aplane orthogonal to the Z-axis direction is a Y-axis direction, and adirection orthogonal to the Z-axis and the Y-axis is an X-axisdirection, and rotational (tilt) directions around the X-axis, Y-axisand Z-axis are θx, θy and θz directions, respectively.

As shown in FIG. 1, exposure apparatus 100 is equipped with an exposurestation (exposure processing area) 200 placed in the vicinity of the +Yside end on a base board 12, a measurement station (measurementprocessing area) 300 placed in the vicinity of the −Y side end on baseboard L2, a stage device 50 that includes two wafer stages WST1 andWST2, their control system and the like. In FIG. 1, wafer stage WST1 islocated in exposure station 200 and a wafer W is held on wafer stageWST1. And, wafer stage WST2 is located in measurement station 300 andanother wafer W is held on wafer stage WST2.

Exposure station 200 is equipped with an illuminations system 10, areticle stage RST, a projection unit PU, a local liquid immersion device8, and the like.

Illumination system 10 includes: a light source; and an illuminationoptical system that has an illuminance uniformity optical systemincluding an optical integrator and the like, and a reticle blind andthe like (none of which are illustrated), as disclosed in, for example,U.S. Patent Application Publication No. 2003/0025690 and the like.

Illumination system 10 illuminates a slit-shaped illumination area TAR,which is defined by the reticle blind (which is also referred to as amasking system), on reticle R with illumination light (exposure light)IL with substantially uniform illuminance. As illumination light IL, ArFexcimer laser light (wavelength: 193 nm) is used as an example.

On reticle stage RST, reticle R having a pattern surface (the lowersurface in FIG. 1) on which a circuit pattern and the like are formed isfixed by, for example, vacuum adsorption. Reticle stage RST can bedriven with a predetermined stroke at a predetermined scanning speed ina scanning direction (which is the Y-axis direction being a lateraldirection of the page surface of FIG. 1) and can also be finely drivenin the X-axis direction, with a reticle stage driving system 11 (notillustrated in FIG. 1, see FIG. 6) including for example, a linear motoror the like.

Positional information within the XY plane (including rotationalinformation in the θz direction) of reticle stage RST is constantlydetected at a resolution of, for example, around 0.25 nm with a reticlelaser interferometer (hereinafter, referred to as a “reticleinterferometer”) 13 via a movable mirror 15 fixed to reticle stage RST(actually, a Y movable mirror (or a retroreflector) that has areflection surface orthogonal to the Y-axis direction and an X movablemirror that has a reflection surface orthogonal to the X-axis directionare arranged). The measurement values of reticle interferometer 13 aresent to a main controller 20 (not illustrated in FIG. 1, see FIG. 6).Incidentally, as disclosed in, for example, PCT InternationalPublication No. 2007/083758 (the corresponding U.S. Patent ApplicationPublication No. 2007/0288121) and the like, the positional informationof reticle stage RST can be measured by an encoder system.

Above reticle stage RST, a pair of reticle alignment systems RA₁ and RA₂by an image processing method, each of which has an imaging device suchas a CCD and uses light with an exposure wavelength (illumination lightIL in the embodiment) as alignment illumination light, are placed (inFIG. 1, reticle alignment system RA₂ hides behind reticle alignmentsystem RA₁ in the depth of the page surface), as disclosed in detail in,for example, U.S. Pat. No. 5,646,413 and the like. Main controller 20detects projected images of a pair of reticle alignment marks (theillustration is omitted) formed on reticle R and a pair of firstfiducial marks on a measurement plate, which is described later, on finemovement stage WFS1 (or WFS2), that correspond to the reticle alignmentmarks via projection optical system PL in a state where the measurementplate is located directly under projection optical system PL, and thepair of reticle alignment systems RA₁ and RA₂ are used to detect apositional relation between the center of a projection area of a patternof reticle R by projection optical system PL and a fiducial position onthe measurement plate, i.e. the center of the pair of the first fiducialmarks, according to such detection performed by main controller 20. Thedetection signals of reticle alignment systems RA₁ and RA₂ are suppliedto main controller 20 (see FIG. 6) via a signal processing system thatis not illustrated. Incidentally, reticle alignment systems RA₁ and RA₂do not have to be arranged. In such a case, it is preferable that adetection system that has a light-transmitting section (photodetectionsection) arranged at a fine movement stage, which is described later on,is installed so as to detect projected images of the reticle alignmentmarks, as disclosed in, for example, U.S. Patent Application PublicationNo. 2002/0041377 and the like.

Projection unit PU is placed below reticle stage EST in FIG. 1.Projection unit PU is supported, via a flange section FLG that is fixedto the outer periphery of projection unit PU, by a main frame (which isalso referred to as a metrology frame) BD that is horizontally supportedby a support member that is not illustrated. Main frame BD can beconfigured such that vibration from the outside is not transmitted tothe main frame or the main frame does not transmit vibration to theoutside, by arranging a vibration isolating device or the like at thesupport member. Projection unit PU includes a barrel 40 and projectionoptical system PL held within barrel 40. As projection optical systemPL, for example, a dioptric system that is composed of a plurality ofoptical elements (lens elements) that are disposed along optical axis AXparallel to the Z-axis direction is used. Projection optical system PLis, for example, both-side telecentric and has a predeterminedprojection magnification (e.g. one-quarter, one-fifth, one-eighth times,or the like). Therefore, when illumination area IAR on reticle R isilluminated with illumination light IL from illumination system 10,illumination light IL passes through reticle R whose pattern surface isplaced substantially coincident with a first plane (object plane) ofprojection optical system PL. Then, a reduced image of a circuit pattern(a reduced image of a part of a circuit pattern) of reticle R withinillumination area IAR is formed in an area (hereinafter, also referredto as an exposure area) IA that is conjugate to illumination area TARdescribed above on wafer W, which is placed on the second plane (imageplane) side of projection optical system PL and whose surface is coatedwith a resist (sensitive agent), via projection optical system PL(projection unit PU). Then, by moving reticle R relative to illuminationarea IAR (illumination light IL) in the scanning direction (Y-axisdirection) and also moving wafer W relative to exposure area IA(illumination light IL) in the scanning direction (Y-axis direction) bysynchronous drive of reticle stage RST and wafer stage WST1 (or WST2),scanning exposure of one shot area (divided area) on wafer W isperformed. Accordingly, a pattern of reticle R is transferred onto theshot area. More specifically, in the embodiment, a pattern of reticle Ris generated on wafer W by illumination system 10 and projection opticalsystem PL, and the pattern is formed on wafer W by exposure of asensitive layer (resist layer) on wafer W with illumination light(exposure light) IL. In this case, projection unit PU is held by mainframe BD, and in the embodiment, main frame BD is substantiallyhorizontally supported by a plurality (e.g. three or four) of supportmembers placed on an installation surface (such as a floor surface) eachvia a vibration isolating mechanism. Incidentally, the vibrationisolating mechanism can be placed between each of the support membersand main frame BD. Further, as disclosed in, for example, PCTInternational Publication No. 2006/038952, main frame BD (projectionunit PU) can be supported in a suspended manner by a main frame member(not illustrated) placed above projection unit PU, or a reticle base orthe like.

Local liquid immersion device 8 includes a liquid supply device 5, aliquid recovery device 6 (none of which are illustrated in FIG. 1, seeFIG. 6), and a nozzle unit 32 and the like. As shown in FIG. 1, nozzleunit 32 is supported in a suspended manner by main frame BD thatsupports projection unit PU and the like, via a support member that isnot illustrated, so as to enclose the periphery of the lower end ofbarrel 40 that holds an optical element closest to the image plane side(wafer W side) that configures projection optical system PL, which is alens (hereinafter, also referred to as a “tip lens”) 191 in this case.Nozzle unit 32 is equipped with a supply opening and a recovery openingof a liquid Lq, a lower surface to which wafer W is placed so as to beopposed and at which the recovery opening is arranged, and a supply flowchannel and a recovery flow channel that are respectively connected to aliquid supply pipe 31A and a liquid recovery pipe 31B (none of which areillustrated in FIG. 1, see FIG. 2). One end of a supply pipe (notillustrated) is connected to liquid supply pipe 31A, while the other endof the supply pipe is connected to liquid supply device 5, and one endof a recovery pipe (not illustrated) is connected to liquid recoverypipe 31B, while the other end of the recovery pipe is connected toliquid recovery device 6.

In the embodiment, main controller 20 controls liquid supply device 5(see FIG. 7) to supply the liquid to the space between tip lens 191 andwafer W and also controls liquid recovery device 6 (see FIG. 7) torecover the liquid from the space between tip lens 191 and wafer W. Onthis operation, main controller 20 controls the quantity of the suppliedliquid and the quantity of the recovered liquid in order to hold aconstant quantity of liquid Lq (see FIG. 1) while constantly replacingthe liquid in the space between tip lens 191 and wafer W. In theembodiment, as the liquid described above, a pure water (with arefractive index n≈1.44) that transmits the ArF excimer laser light (thelight with a wavelength of 193 nm) is to be used.

Measurement station 300 is equipped with an alignment device 99 arrangedat main frame BD. Alignment device 99 includes five alignment systemsAL1 and AL2 ₁ to AL2 ₄ shown in FIG. 2, as disclosed in, for example,U.S. Patent Application Publication No. 2008/0088843 and the like. To bemore specific, as shown in FIG. 2, a primary alignment system AL1 isplaced in a state where its detection center is located at a position apredetermined distance apart on the −Y side from optical axis AX, on astraight line (hereinafter, referred to as a reference axis) LV thatpasses through the center of projection unit PU (which is optical axisAX of projection optical system, PL, and in the embodiment, which alsocoincides with the center of exposure area IA described previously) andis parallel to the Y-axis. On one side and the other side in the X-axisdirection with primary alignment system AL1 in between, secondaryalignment systems AL2 ₁ and AL2 ₂, and AL2 ₃ and AL2 ₄, whose detectioncenters are substantially symmetrically placed with respect to referenceaxis LV, are arranged respectively. More specifically, the detectioncenters of the five alignment systems AL1 and AL2 ₁ to AL2 ₄ are placedalong a straight line (hereinafter, referred to as a reference axis) Lathat vertically intersects reference axis LV at the detection center ofprimary alignment system AL1 and is parallel to the X-axis. Note that aconfiguration including the five alignment systems AL1 and AL2 ₁ to AL2₄ and a holding device (slider) that holds these alignment systems isshown as alignment device 99 in FIG. 1. As disclosed in, for example,U.S. Patent Application Publication No. 2009/0233234 and the like,secondary alignment systems AL2 ₁ to AL2 ₄ are fixed to the lowersurface of main frame BD via the movable slider (see FIG. 1), and therelative positions of the detection areas of the secondary alignmentsystems are adjustable at least in the X-axis direction with a drivemechanism that is not illustrated.

In the embodiment, as each of alignment systems AL1 and AL2 ₁ to AL2 ₄,for example, an FIA (Field Image Alignment) system by an imageprocessing method is used. The configurations of alignment systems AL1and AL2 ₁ to AL2 ₄ are disclosed in detail in, for example, PCTInternational Publication No. 2008/056735 and the like. The imagingsignal from each of alignment systems AL1 and AL2 ₁ to AL2 ₄ is suppliedto main controller 20 (see FIG. 6) via a signal processing system thatis not illustrated.

Note that exposure apparatus 100 has a first loading position where acarriage operation of a wafer is performed with respect to wafer stageWST1 and a second loading position where a carriage operation of a waferis performed with respect to wafer stage WST2, although the loadingpositions are not illustrated. In the case of the embodiment, the firstloading position is arranged on the surface plate 14A side and thesecond loading position is arranged on the surface plate 14B side.

As shown in FIG. 1, stage device 50 is equipped with base board 12, apair of surface plates 14A and 14B placed above base board 12 (in FIG.1, surface plate 14B hides behind surface plate 14 in the depth of thepage surface), the two wafer stages WST1 and WST2 that move on a guidesurface parallel to the XY plane that is formed by the upper surfaces ofthe pair of surface plates 14A and 14B, tube carriers TCa and TCb (tubecarrier TCb is not illustrated in FIG. 1, see the drawings such as FIGS.2 and 3) that are respectively connected to wafer stages WST1 and WST2via piping/wiring systems (hereinafter, referred to as tubes for thesake of convenience) Ta₂ and Tb₂ (not illustrated in FIG. 1, see FIGS. 2and 3), a measurement system that measures positional information ofwafer stages WST1 and WST2, and the like. The electric power for varioustypes of sensors and actuators such as motors, the coolant fortemperature adjustment to the actuators, the pressurized air for airbearings, and the like are supplied from the outside to wafer stagesWST1 and WST2 via tubes Ta₂ and Tb₂, respectively. Note that, in thedescription below, the electric power, the coolant for temperatureadjustment, the pressurized air and the like are also referred to as thepower usage collectively. In the case where a vacuum suction force isnecessary, the force for vacuum (negative pressure) is also included inthe power usage.

Base board 12 is made up of a member having a tabular outer shape, andas shown in FIG. 1, is substantially horizontally (parallel to the XYplane) supported via a vibration isolating mechanism (the illustrationis omitted) on a floor surface 102. In the center portion in the X-axisdirection of the upper surface of base board 12, a recessed section 12 a(recessed groove) extending in a direction parallel to the Y-axis isformed, as shown in FIG. 3. On the upper surface side of base board 12(excluding a portion where recessed section 12 a is formed, in thiscase), a coil unit CU is housed that includes a plurality of coilsplaced in a matrix shape with the XY two-dimensional directions servingas a row direction and a column direction. Incidentally, the vibrationisolating mechanism does not necessarily have to be arranged.

As shown in FIG. 2, surface plates 14A and 14B are each made up of arectangular plate-shaped member whose longitudinal direction is in theY-axis direction in a planar view (when viewed from above) and arerespectively placed on the −X side and the +X side of reference axis LV.Surface plate 14A and surface plate 14B are placed with a very narrowgap therebetween in the X-axis direction, symmetric with respect toreference axis LV. By finishing the upper surface (the +Z side surface)of each of surface plates 14A and 14B such that the upper surface has avery high flatness degree, it is possible to make the upper surfacesfunction as a guide surface with respect to the Z-axis direction usedwhen each of wafer stages WST1 and WST2 moves following the XY plane.Alternatively, a configuration can be employed in which a force in theZ-axis direction is made to act on wafer stages WST1 and WST2 by planarmotors, which are described later on, to magnetically levitate waferstages WST1 and WST2 above surface plates 14A and 14B. In the case ofthe embodiment, the configuration that uses the planar motors isemployed and static gas bearings are not used, and therefore, theflatness degree of the upper surfaces of surface plates 14A and 14B doesnot have to be so high as in the above description.

As shown in FIG. 3, surface plates 14A and 14B are supported on uppersurfaces 12 b of both side portions of recessed section 12 a of baseboard 12 via air bearings (or rolling bearings) that are notillustrated.

surface plates 14A and 14B respectively have first sections 14A₁ and14B₁ each having a relatively thin plate shape on the upper surface ofwhich the guide surface is formed, and second sections 14A₂ and 14B₂each having a relatively thick plate shape and being short in the X-axisdirection that are integrally fixed to the lower surfaces of firstsections 14A₁ and 14B₁, respectively. The end on the +X side of firstsection 14A₁, of surface plate 14A slightly overhangs, to the +X side,the end surface on the +X side of second section 14A₂, and the end onthe −X side of first section 14B₁ of surface plate 14B slightlyoverhangs, to the −X side, the end surface on the −X side of secondsection 14B₂. However, the configuration is not limited to theabove-described one, and a configuration can be employed in which theoverhangs are not arranged.

Inside each of first sections 14A₁ and 14B₁, a coil unit (theillustration is omitted) is housed that includes a plurality of coilsplaced in a matrix shape with the XY two-dimensional directions servingas a row direction and a column direction. The magnitude and directionof the electric current supplied to each of the plurality of coils thatconfigure the respective coil units are controlled by main controller 20(see FIG. 6).

Inside (on the bottom portion of) second section 14A₂ of surface plate14A, a magnetic unit MUa, which is made up of a plurality of permanentmagnets (and yokes that are not illustrated) placed in a matrix shapewith the XY two-dimensional directions serving as a row direction and acolumn direction, is housed so as to correspond to coil unit CU housedon the upper surface side of base board 12. Magnetic unit MUaconfigures, together with coil unit CU of base board 12, a surface platedriving system 60A (see FIG. 6) that is made up of a planar motor by theelectromagnetic force (Lorentz force) drive method that is disclosed in,for example, U.S. Patent Application Publication No. 2003/0085676 andthe like. Surface plate driving system 60A generates a drive force thatdrives surface plate 14A in directions of three degrees of freedom (X,Y, θz) within the XY plane.

Similarly, inside (on the bottom portion of) second section 14B₂ ofsurface plate 14B, a magnetic unit MUb made up of a plurality ofpermanent magnets (and yokes that are not illustrated) is housed thatconfigures, together with coil unit CU of base board 12, a surface platedriving system 60B (see FIG. 6) made up of a planar motor that drivessurface plate 14B in the directions of three degrees of freedom withinthe XY plane. Incidentally, the placement of the coil unit and themagnetic unit of the planar motor that configures each of surface platedriving systems 60A and 60B can be reverse (a moving coil type that hasthe magnetic unit on the base board side and the coil unit on thesurface plate side) to the above-described case (a moving magnet type).

Positional information of surface plates 14A and 14B in the directionsof three degrees of freedom is obtained (measured) independently fromeach other by a first surface plate position measuring system 69A and asecond surface plate position measuring system 69B (see FIG. 6),respectively, which each include, for example, an encoder system. Theoutput of each of first surface plate position measuring system 69A andsecond surface plate position measuring system 69B is supplied to maincontroller 20 (see FIG. 6), and main controller 20 controls themagnitude and direction of the electric current supplied to therespective coils that configure the coil units of surface plate drivingsystems 60A and 60B, using (based on) the outputs of surface plateposition measuring systems 69A and 69B, thereby controlling therespective positions of surface plates 14A and 14B in the directions ofthree degrees of freedom within the XY plane, as needed. Main controller20 drives surface plates 14A and 14B via surface plate driving systems60A and 60B using (based on) the outputs of surface plate positionmeasuring systems 69A and 69B to return surface plates 14A and 14B tothe reference position of the surface plates such that the movementdistance of surface plates 14A and 14B from the reference position fallswithin a predetermined range, when surface plates 14A and 14B functionas countermasses to be described later on. More specifically, surfaceplate driving systems 60A and 603 are used as trim motors.

While the configurations of first surface plate position measuringsystem 69A and second surface plate position measuring system 69B arenot especially limited, an encoder system can be used in which, forexample, encoder heads, which obtain (measure) positional information ofthe respective surface plates 14A and 14B in the directions of threedegrees of freedom within the XY plane by irradiating measurement beamson scales (e.g. two-dimensional gratings) placed on the lower surfacesof second sections 14A₂ and 14B₂ respectively and using reflected light(diffraction light from the two-dimensional gratings) obtained by theirradiation, are placed at base board 12 (or the encoder heads areplaced at second sections 14A₂ and 14B₂ and scales are placed at baseboard 12, respectively). Incidentally, it is also possible to obtain(measure) the positional information of surface plates 14A and 14B by,for example, an optical interferometer system or a measurement systemthat is a combination of an optical interferometer system and an encodersystem.

One of the wafer stages, wafer stage WST1 is equipped with a finemovement stage (which is also referred to as a table) WFS1 that holdswafer W and a coarse movement stage WCS1 having a rectangular frameshape that encloses the periphery of fine movement stage WFS1, as shownin FIG. 2. The other of the wafer stages, wafer stage WST2 is equippedwith a fine movement stage WFS2 that holds wafer W and a coarse movementstage WCS2 having a rectangular frame shape that encloses the peripheryof fine movement stage WFS2, as shown in FIG. 2. As is obvious from FIG.2, wafer stage WST2 has completely the same configuration including thedrive system, the position measuring system and the like, as Wafer stageWST1 except that wafer stage WST2 is placed in a state laterallyreversed with respect to wafer stage WST1. Consequently, in thedescription below, wafer stage WST1 is representatively focused on anddescribed, and wafer stage WST2 is described only in the case where suchdescription is especially needed.

As shown in FIG. 4A, coarse movement stage WCS1 has a pair of coarsemovement slider sections 90 a and 90 b which are placed parallel to eachother, spaced apart in the Y-axis direction, and each of which is madeup of a rectangular parallelepiped member whose longitudinal directionis in the X-axis direction, and a pair of coupling members 92 a and 92 beach of which is made up of a rectangular parallelepiped member whoselongitudinal direction is in the Y-axis direction, and which couple thepair of coarse movement slider sections 90 a and 90 b with one ends andthe other ends thereof in the Y-axis direction. More specifically,coarse movement stage WCS1 is formed into a rectangular frame shape witha rectangular opening section, in its center portion, that penetrates inthe Z-axis direction.

Inside (on the bottom portions of) coarse movement slider sections 90 aand 90 b, as shown in FIGS. 4B and 4C, magnetic units 96 a and 96 b arehoused respectively. Magnetic units 96 a and 96 b correspond to the coilunits housed inside first sections 14A₁ and 14B₁ of surface plates 14Aand 14B, respectively, and are each made of up a plurality of magnetsplaced in a matrix shape with the XY two-dimensional directions servingas a row direction and a column direction. Magnetic units 96 a and 96 bconfigure, together with the coil units of surface plates 14A and 14B, acoarse movement stage driving system 62A (see FIG. 6) that is made up ofa planar motor by the electromagnetic force (Lorentz force) drive methodthat is capable of generating drive forces in the directions of sixdegrees of freedom to coarse movement stage WCS1, which is disclosed in,for example, U.S. Patent Application Publication No. 2003/0085676 andthe like. Further, similar thereto, magnetic units, which coarsemovement stage WCS2 (see FIG. 2) of wafer stage WST2 has, and the coilunits of surface plates 14A and 14B configure a coarse movement stagedriving system 62B (see FIG. 6) made up of a planar motor. In this case,since a force in the Z-axis direction acts on coarse movement stage WCS1(or WCS2), the coarse movement stage is magnetically levitated abovesurface plates 14A and 14B. Therefore, it is not necessary to use staticgas beatings for which relatively high machining accuracy is required,and thus it becomes unnecessary to increase the flatness degree of theupper surfaces of surface plates 14A and 14B.

Incidentally, while coarse movement stages WCS1 and WCS2 of theembodiment each have the configuration in which only coarse movementslider sections 90 a and 90 b have the magnetic units of the planarmotors, this is not intended to be limiting, and the magnetic unit canbe placed also at coupling members 92 a and 92 b. Further, the actuatorsto drive coarse movement stages WCS1 and WCS2 are not limited to theplanar motors by the electromagnetic force (Lorentz force) drive method,but for example, planar motors by a variable magnetoresistance drivemethod or the like can be used. Further, the drive directions of coarsemovement stages WCS1 and WCS2 are not limited to the directions of sixdegrees of freedom, but can be, for example, only directions of threedegrees of freedom (X, Y, θz) within the XY plane. In this case, coarsemovement stages WCS1 and WCS2 should be levitated above surface plates14A and 14B, for example, using static gas bearings (e.g. air bearings).Further, in the embodiment, while the planar motor of a moving magnettype is used as each of coarse movement stage driving systems 62A and62B, this is not intended to be limiting, and a planar motor of a movingcoil type in which the magnetic unit is placed at the surface plate andthe coil unit is placed at the coarse movement stage can also be used.

On the side surface on the −Y side of coarse movement slider section 90a and on the side surface on the +Y side of coarse movement slidersection 90 b, guide members 94 a and 94 b that function as a guide usedwhen fine movement stage WFS1 is finely driven are respectively fixed.As shown in FIG. 4B, guide member 94 a is made up of a member having anL-like sectional shape arranged extending in the X-axis direction andits lower surface is placed flush with the lower surface of coarsemovement slider section 90 a. Guide member 94 b is configured and placedsimilar to guide member 94 a, although guide member 94 b is bilaterallysymmetric to guide member 94 a.

Inside (on the bottom surface of) guide member 94 a, a pair of coilunits CUa and CUb, each of which includes a plurality of coils placed ina matrix shape with the XY two-dimensional directions serving as a rowdirection and a column direction, are housed at a predetermined distancein the X-axis direction (see FIG. 4A). Meanwhile, inside (on the bottomportion of) guide member 94 b, one coil unit CUc, which includes aplurality of coils placed in a matrix shape with the XY two-dimensionaldirections serving as a row direction and a column direction, is housed(see FIG. 4A). The magnitude and direction of the electric currentsupplied to each of the coils that configure coil units CUa to CUc arecontrolled by main controller 20 (see FIG. 6).

Coupling members 92 a and 92 b are formed to be hollow, and pipingmembers, wiring members and the like, which are not illustrated, used tosupply the power usage to fine movement stage WFS1 are housed inside.Inside coupling members 92 a and/or 92 b, various types of opticalmembers (e.g. an aerial image measuring instrument, an unevenilluminance measuring instrument, an illuminance monitor, a wavefrontaberration measuring instrument, and the like) can be housed.

In this case, when wafer stage WST1 is driven withacceleration/deceleration in the Y-axis direction on surface plate 14A,by the planar motor that configures coarse movement stage driving system62A (e.g. when wafer stage WST1 moves between exposure station 200 andmeasurement station 300), surface plate 14A is driven in a directionopposite to wafer stage WST1 according to the so-called law of actionand reaction (the law of conservation of momentum) owing to the actionof a reaction force by the drive of wafer stage WST1. Further, it isalso possible to make a state where the law of action and reactiondescribed above does not hold, by generating a drive force in the Y-axisdirection with surface plate driving system 60A.

Further, when wafer stage WST 2 is driven in the Y-axis direction onsurface plate 14B, surface plate 14B is also driven in a directionopposite to wafer stage WST2 according to the so-called law of actionand reaction (the law of conservation of momentum) owing to the actionof a reaction force of a drive force of wafer stage WST2. Morespecifically, surface plates 14A and 14B function as the countermassesand the momentum of a system composed of wafer stages WST1 and WST2 andsurface plates 14A and 14B as a whole is conserved and movement of thecenter of gravity does not occur. Consequently, any inconveniences donot arise such as the uneven loading acting on surface plates 14A and14B owing to the movement of wafer stages WST1 and WST2 in the Y-axisdirection. Incidentally, regarding wafer stage WST2 as well, it ispossible to make a state where the law of action and reaction describedabove does not hold, by generating a drive force in the Y-axis directionwith surface plate driving system 60B.

Further, on movement in the X-axis direction of wafer stages WST1 andWST2, surface plates 14A and 14B function as the countermasses owing tothe action of a reaction force of the drive force.

As shown in FIGS. 4A and 4B, fine movement stage WFS1 is equipped with amain section 80 made up of a member having a rectangular shape in aplanar view, a pair of fine movement slider sections 84 a and 84 b fixedto the side surface on the +Y side of main section 80, and a finemovement slider section 84 c fixed to the side surface on the −Y side ofmain section 80.

Main section 80 is formed by a material with a relatively smallcoefficient of thermal expansion, e.g., ceramics, glass or the like, andis supported by coarse movement stage WCS1 in a noncontact manner in astate where the bottom surface of the main section is located flush withthe bottom surface of coarse movement stage WCS1. Main section 80 can behollowed for reduction in weight. Incidentally, the bottom surface ofmain section 80 does not necessarily have to be flush with the bottomsurface of coarse movement stage WCS1.

In the center of the upper surface of main section 80, a wafer holder(not illustrated) that holds wafer W by vacuum adsorption or the like isplaced. In the embodiment, the wafer holder by a so-called pin chuckmethod is used in which a plurality of support sections (pin members)that support wafer W are formed, for example, within an annularprotruding section (rim section), and the wafer holder, whose onesurface (front surface) serves as a wafer mounting surface, has atwo-dimensional grating RG to be described later and the like arrangedon the other surface (back surface) side. Incidentally, the wafer holdercan be formed integrally with fine movement stage WFS1 (main section80), or can be fixed to main section 80 so as to be detachable via, forexample, a holding mechanism such as an electrostatic chuck mechanism ora clamp mechanism. In this case, grating RG is to be arranged on theback surface side of main section 80. Further, the wafer holder can befixed to main section 80 by an adhesive agent or the like. On the uppersurface of main section 80, as shown in FIG. 4A, a plate(liquid-repellent plate) 82, in the center of which a circular openingthat is slightly larger than wafer W (wafer holder) is formed and whichhas a rectangular outer shape (contour) that corresponds to main section80, is attached on the outer side of the wafer holder (mounting area ofwafer W). The liquid-repellent treatment against liquid Lq is applied tothe surface of plate 82 (the liquid-repellent surface is formed). In theembodiment, the surface of plate 82 includes a base material made up ofmetal, ceramics, glass or the like, and a film of liquid-repellentmaterial formed on the surface of the base material. Theliquid-repellent material includes, for example, PFA (Tetra fluoroethylene-perfluoro alkylvinyl ether copolymer), PTFE (Poly tetra fluoroethylene), Teflon (registered trademark) or the like. Incidentally, thematerial that forms the film can be an acrylic-type resin or asilicon-series resin. Further, the entire plate 82 can be formed with atleast one of the PFA, PTFE, Teflon (registered trademark), acrylic-typeresin and silicon-series resin. In the embodiment, the contact angle ofthe upper surface of plate 82 with respect to liquid Lq is, for example,more than or equal to 90 degrees. On the surface of coupling member 92 bdescribed previously as well, the similar liquid-repellent treatment isapplied.

Plate 82 is fixed to the upper surface of main section 80 such that theentire surface (or a part of the surface) of plate 82 is flush with thesurface of wafer W. Further, the surfaces of plate 82 and wafer W arelocated substantially flush with the surface of coupling member 92 bdescribed previously. Further, in the vicinity of a corner on the +Xside located on the +Y side of plate 82, a circular opening is formed,and a measurement plate FM1 is placed in the opening without any gaptherebetween in a state substantially flush with the surface of wafer W.On the upper surface of measurement plate FM1, the pair of firstfiducial marks to be respectively detected by the pair of reticlealignment systems RA₁ and RA₂ (see FIGS. 1 and 6) described earlier anda second fiducial mark to be detected by primary alignment system AL1(none of the marks are illustrated) are formed. In fine movement stageWFS2 of wafer stage WST2, as shown in FIG. 2, in the vicinity of acorner on the −X side located on the +Y side of plate 82, a measurementplate FM2 that is similar to measurement plate FM1 is fixed in a statesubstantially flush with the surface of wafer W. Incidentally, insteadof attaching plate 82 to fine movement stage WFS1 (main section 80), itis also possible, for example, that the wafer holder is formedintegrally with fine movement stage WFS1 and the liquid-repellenttreatment is applied to the peripheral area, which encloses the waferholder (the same area as plate 82 (which may include the surface of themeasurement plate)), of the upper surface of fine movement stage WFS1and the liquid repellent surface is formed.

In the center portion of the lower surface of main section 80 of finemovement stage WFS1, as shown in FIG. 4B, a plate having a predeterminedthin plate shape, which is large to the extent of covering the waferholder (mounting area of wafer W) and measurement plate FM1 (ormeasurement plate FM2 in the case of fine movement stage WFS2), isplaced in a state where its lower surface is located substantially flushwith the other section (the peripheral section) (the lower surface ofthe plate does not protrude below the peripheral section). On onesurface (the upper surface (or the lower surface)) of the plate,two-dimensional grating RG (hereinafter, simply referred to as gratingRG) is formed. Grating RG includes a reflective diffraction grating (Xdiffraction grating) whose periodic direction is in the X-axis directionand a reflective diffraction grating (Y diffraction grating) whoseperiodic direction is in the Y-axis direction. The plate is formed by,for example, glass, and grating RG is created by graving the graduationsof the diffraction gratings at a pitch, for example, between 138 nm to 4μm, e.g. at a pitch of 1 μm. Incidentally, grating RG can also cover theentire lower surface of main section 80. Further, the type of thediffraction grating used for grating RG is not limited to the one onwhich grooves or the like are mechanically formed, but for example, adiffraction grating that is created by exposing interference fringes ona photosensitive resin can also be employed. Incidentally, theconfiguration of the plate having a thin plate shape is not necessarilylimited to the above-described one.

As shown in FIG. 4A, the pair of fine movement slider sections 84 a and84 b are each a plate-shaped member having a toughly square shape in aplanar view, and are placed apart at a predetermined distance in theX-axis direction, on the side surface on the +Y side of main section 80.Fine movement slider section 84 c is a plate-shaped member having arectangular shape elongated in the X-axis direction in a planar view,and is fixed to the side surface on the −Y side of main section 80 in astate where one end and the other end in its longitudinal direction arelocated on straight lines parallel to the Y-axis that are substantiallycollinear with the centers of fine movement slider sections 84 a and 84b.

The pair of fine movement slider sections 84 a and 84 b are respectivelysupported by guide member 94 a described earlier, and fine movementslider section 84 c is supported by guide member 94 b. Morespecifically, fine movement stage WFS is supported at three noncollinearpositions with respect to coarse movement stage WCS.

Inside fine movement slider sections 84 a to 84 c, magnetic units 98 a,98 b and 98 c, which are each made up of a plurality of permanentmagnets (and yokes that are not illustrated) placed in a matrix shapewith the XY two-dimensional directions serving as a row direction and acolumn direction, are housed, respectively, so as to correspond to coilunits CUa to CUc that guide sections 94 a and 94 b of coarse movementstage WCS1 have. Magnetic unit 98 a together with coil unit CUa,magnetic unit 98 b together with coil unit CUb, and magnetic unit 98 ctogether with coil unit CUc respectively configure three planar motorsby the electromagnetic force (Lorentz force) drive method that arecapable of generating drive forces in the X-axis, Y-axis and Z-axisdirections, as disclosed in, for example, U.S. Patent ApplicationPublication No. 2003/0085676 and the like, and these three planar motorsconfigure a fine movement stage driving system 64A (see FIG. 6) thatdrives fine movement stage WFS1 in directions of six degrees of freedom(X, Y, Z, θx, θy and θz).

In wafer stage WST2 as well, three planar motors composed of coil unitsthat coarse movement stage WCS2 has and magnetic units that finemovement stage WFS2 has are configured likewise, and these three planarmotors configure a fine movement stage driving system 64B (see FIG. 6)that drives fine movement stage WFS2 in directions of six degrees offreedom (X, Y, Z, θx, θy and θz).

Fine movement stage WFS1 is movable in the X-axis direction, with alonger stroke compared with the directions of the other five degrees offreedom, along guide members 94 a and 94 b arranged extending in theX-axis direction. The same applies to fine movement stage WFS2.

With the configuration as described above, fine movement stage WFS1 ismovable in the directions of six degrees of freedom with respect tocoarse movement stage WCS1. Further, on this operation, the law ofaction and reaction (the law of conservation of momentum) that issimilar to the previously described one holds owing to the action of areaction force by drive of fine movement stage WFS1. More specifically,coarse movement stage WCS1 functions as the countermass of fine movementstage WFS1, and coarse movement stage WCS1 is S driven in a directionopposite to fine movement stage WFS1. Fine movement stage WFS2 andcoarse movement stage WCS2 has the similar relation.

Note that, in the embodiment, when broadly driving fine movement stageWFS1 (or WFS2) with acceleration/deceleration in the X-axis direction(e.g. in the cases such as when a stepping operation between shot areasis performed during exposure), main controller 20 drives fine movementstage WFS1 (or WSF2) in the X-axis direction by the planar motors thatconfigure fine movement stage driving system 64A (or 64B). Further,along with this drive, main controller 20 gives the initial velocity,which drives coarse movement stage WCS1 (or WCS2) in the same directionas with fine movement stage WFS1 (or WFS2), to coarse movement stageWCS1 (or WCS2), via coarse movement stage driving system 62A (or 62B)(drives coarse movement stage WCS1 (or WCS2) in the same direction aswith fine movement stage WFS1 (or WFS2)). This causes coarse movementstage WCS1 (or WCS2) to function as the so-called countermass and alsocan decrease a movement distance of coarse movement stage WCS1 (or WCS2)in the opposite direction that accompanies the movement of fine movementstage WFS1 (or WFS2) in the X-axis direction (that is caused by areaction force of the drive force). Especially, in the case where finemovement stage WFS1 (or WFS2) performs an operation including the stepmovement in the X-axis direction, or more specifically, fine movementstage WFS1 (or WFS2) performs an operation of alternately repeating theacceleration and the deceleration in the X-axis direction, the stroke inthe X-axis direction needed for the movement of coarse movement stageWCS1 (or WCS2) can be the shortest. On this operation, main controller20 should give coarse movement stage WCS1 (or WCS2) the initial velocitywith which the center of gravity of the entire system of wafer stageWST1 (or WST2) that includes the fine movement stage and the coarsemovement stage performs constant velocity motion in the X-axisdirection. With this operation, coarse movement stage WCS1 (or WCS2)performs a back-and-forth motion within a predetermined range with theposition of fine movement stage WFS1 (or WFS2) serving as a reference.Consequently, as the movement stroke of coarse movement stage WCS1 (orWCS2) in the X-axis direction, the distance that is obtained by addingsome margin to the predetermined range should be prepared. Such detailsare disclosed in, for example, U.S. Patent Application Publication No.2008/0143994 and the like.

Further, as described earlier, since fine movement stage WFS1 issupported at the three noncollinear positions by coarse movement stageWCS1, main controller 20 can tilt fine movement stage WFS1 (i.e. waferW) at an arbitrary angle (rotational amount) in the ex direction and/orthe θy direction with respect to the XY plane by, for example,appropriately controlling a drive force (thrust) in the Z-axis directionthat is made to act on each of fine movement slider sections 84 a to 84c. Further, main controller 20 can make the center portion of finemovement stage WFS1 bend in the +Z direction (into a convex shape), forexample, by making a drive force in the +θx direction (acounterclockwise direction on the page surface of FIG. 4B) on each offine movement slider sections 84 a and 84 b and also making a driveforce in the −θx direction (a clockwise direction on the page surface ofFIG. 4B) on fine movement slider section 84 c. Further, main controller20 can also make the center portion of fine movement stage WFS1 bend inthe +Z direction (into a convex shape), for example, by making driveforces in the −θy direction and the +θy direction (a counterclockwisedirection and a clockwise direction when viewed from the +Y side,respectively) on fine movement slider sections 84 a and 84 b,respectively. Main controller 20 can also perform the similar operationswith respect to fine movement stage WFS2.

Incidentally, in the embodiment, as fine movement stage driving systems64A and 64B, the planar motors of a moving magnet type are used, butthis is not intended to be limiting, and planar motors of a moving coiltype in which the coil units are placed at the fine movement slidersections of the fine movement stages and the magnetic units are placedat the guide members of the coarse movement stages can also be used.

Between coupling member 92 a of coarse movement stage WCS1 and mainsection 80 of fine movement stage WFS1, as shown in FIG. 4A, a pair oftubes 86 a and 86 b used to transmit the power usage, which is suppliedfrom the outside to coupling member 92 a, to fine movement stage WFS1are installed. Incidentally, although the illustration is omitted in thedrawings including FIG. 4A, actually, the pair of tubes 86 a and 86 bare each made up of a plurality of tubes. One ends of tubes 86 a and 86b are connected to the side surface on the +X side of coupling member 92a and the other ends are connected to the inside of main section 80,respectively via a pair of recessed sections 80 a (see FIG. 4C) with apredetermined depth each of which is formed from the end surface on the−X side toward the +X direction with a predetermined length, on theupper surface of main section 80. As shown in FIG. 4C, tubes 86 a and 86b are configured not to protrude above the upper surface of finemovement stage WFS1. Between coupling member 92 a of coarse movementstage WCS2 and main section 80 of fine movement stage WFS2 as well, asshown in FIG. 2, a pair of tubes 86 a and 86 b used to transmit thepower usage, which is supplied from the outside to coupling member 92 a,to fine movement stage WFS2 are installed.

In the embodiment, as each of fine movement stage driving systems 64Aand 64B, the three planar motors of a moving magnet type are used, andtherefore, the power usage other than the electric power is transmittedbetween the coarse movement stage and the fine movement stage via tubes86 a and 86 b. Incidentally, transmission of the power usage between thecoarse movement stage and the fine movement stage can be performed in anoncontact manner by employing the configuration and the method asdisclosed in, for example, PCT International publication No 2004/100237,instead of tubes 86 a and 86 b.

As shown in FIG. 2, one of the tube carriers, tube carrier TCa isconnected to the piping member and the wiring member inside couplingmember 92 a of coarse movement stage WCS1 via tube Ta₂. As shown in FIG.3, tube carrier TCa is placed on a stepped section formed at the end onthe −X side of base board 12. Tube carrier TCa is driven in the Y-axisdirection following wafer stage WST1, by an actuator such as a linermotor, on the stepped section of base board 12.

As shown in FIG. 3, the other of the tube carriers, tube carrier TCb isplaced on a stepped section formed at the end on the +X side of baseboard 12, and is connected to the piping member and the wiring memberinside coupling member 92 a of coarse movement stage WCS2 via tube Tb₂(see FIG. 2). Tube carrier TCb is driven in the Y-axis directionfollowing wafer stage WST2, by an actuator such as a liner motor, on thestepped section of base board 12.

As shown in FIG. 3, one ends of tubes Ta₁ and Tb₁ are connected to tubecarriers TCa and TCb respectively, while the other ends of tubes Ta₁ andTb₁ are connected to a power usage supplying device externally installedthat is not illustrated (e.g. an electric power supply, a gas tank, acompressor, a vacuum pump or the like). The power usage supplied fromthe power usage supplying device to tube carrier TCa via tube Ta₁ issupplied to fine movement stage WFS1 via tube Ta₂, the piping member andthe wiring member, which are not illustrated, housed in coupling member92 a of coarse movement stage WCS1, and tubes 86 a and 86 b. Similarly,the power usage supplied from the power usage supplying device to tubecarrier TCb via tube Tb₁ is supplied to fine movement stage WFS2 viatube Tb₂, the piping member and the wiring member, which are notillustrated, housed in coupling member 92 a of coarse movement stageWCS2, and tubes 86 a and 86 b.

Next, a measurement system that measures positional information of waferstages WST1 and WST2 is described. Exposure apparatus 100 has a finemovement stage position measuring system 70 (see FIG. 6) to measurepositional information of fine movement stages WFS1 and WFS2 and coarsemovement stage position measuring systems 68A and 68B (see FIG. 6) tomeasure positional information of coarse movement stages WCS1 and WCS2respectively.

Fine movement stage position measuring system 70 has a measurement bar71 shown in FIG. 1. Measurement bar 71 is placed below first sections14A₁ and 14B₁ that the pair of surface plates 14A and 14B respectivelyhave, as shown in FIG. 3. As is obvious from FIGS. 1 and 3, measurementbar 71 is made up of a beam-like member having a rectangular sectionalshape with the Y-axis direction serving as its longitudinal direction,and both ends in the longitudinal direction are each fixed to main frameBD in a suspended state via a suspended member 74. More specifically,main frame BD and measurement bar 71 are integrated. Incidentally, inthe case where a configuration that does not block the movement of thewafer stages is employed for the beam-like member, the support method ofthe beam-like member is not limited to the both ends support but one endin the longitudinal direction can be cantilevered. Further, thebeam-like member should be placed below base board 12 described earlier.Furthermore, while the beam-like member is supported by main frame BD,the beam-like member can be arranged on the installation surface (suchas a floor surface) via a vibration isolating mechanism. In this case,it is preferable to arrange a measurement device that measures therelative positional relation between main frame BD and the beam-likemember. The beam-like member can also be referred to as a member formeasurement or the like.

The +Z side half (upper half) of measurement bar 71 is placed betweensecond section 14A₂ of surface plate 14A and second section 14B₂ ofsurface plate 14B, and the −Z side half (lower half) is housed insiderecessed section 12 a formed at base board 12. Further, a predeterminedclearance is formed between measurement bar 71 and each of surfaceplates 14A and 14B and base board 12, and measurement bar 71 is in astate mechanically noncontact with the members other than main frame BD.Measurement bar 71 is formed by a material with a relatively lowcoefficient of thermal expansion (e.g. invar, ceramics, or the like).Incidentally, the shape of measurement bar 71 is not limited inparticular. For example, it is also possible that the measurement memberhas a circular cross section (a cylindrical shape), or a trapezoidal ortriangle cross section. Further, the measurement bar does notnecessarily have to be formed by a longitudinal member such as abar-like member or a beam-like member.

At measurement bar 71, as shown in FIG. 5, a first measurement headgroup 72 used when measuring positional information of the fine movementstage (WFS1 or WFS2) located below projection unit PU and a secondmeasurement head group 73 used when measuring positional information ofthe fine movement stage (WFS1 or WFS2) located below alignment device 99are arranged. Incidentally, alignment systems AL1 and AL2 ₁ to AL2 ₄ areshown in virtual lines (two-dot chain lines) in FIG. 5 in order to makethe drawing easy to understand. Further, in FIG. 5, the reference signsof alignment systems AL2 ₁ to AL2 ₄ are omitted.

As shown in FIG. 5, first measurement head group 72 is placed belowprojection unit PU and includes a one-dimensional encoder head forX-axis direction measurement (hereinafter, shortly referred to as an Xhead or an encoder head) 75 x, a pair of one-dimensional encoder headsfor Y-axis direction measurement (hereinafter, shortly referred to as Yheads or encoder heads) 75 ya and 75 yb, and three Z heads 76 a, 76 band 76 c.

X head 75 x, Y heads 75 ya and 75 yb and the three Z heads 76 a to 76 care placed in a state where their positions do not vary, insidemeasurement bar 71. X head 75 x is placed on reference axis LV, and Yheads 75 ya and 75 yb are placed at the same distance apart from X head75 x, on the −X side and the side, respectively. In the embodiment, aseach of the three encoder heads 75 x, 75 ya and 75 yb, a diffractioninterference type head having a configuration in which a light source, aphotodetection system (including a photodetector) and various types ofoptical systems are unitized is used, which is similar to the encoderhead disclosed in, for example, PCT International Publication No.2007/083758 (the corresponding U.S. Patent Application Publication No.2007/0288121) and the like.

When wafer stage WST1 (or WST2) is located directly under projectionoptical system PL (see FIG. 1), X head 75 x and Y heads 75 ya and 75 ybeach irradiate a measurement beam on grating RG (see FIG. 4B) placed onthe lower surface of fine movement stage WFS1 (or WFS2), via a gapbetween surface plate 14A and surface plate 14B or a light-transmittingsection (e.g. an opening) formed at first section 14A₁ of surface plate14A and first section 14B₁ of surface plate 14B. Further, X head 75 xand Y heads 75 ya and 75 yb each receive diffraction light from gratingRG, thereby obtaining positional information within the XY plane (alsoincluding rotational information in the θz direction) of fine movementstage WFS1 (or WFS2). More specifically, an X liner encoder 51 (see FIG.6) is configured of X head 75 x that measures the position of finemovement stage WFS1 (or WFS2) in the X-axis direction using the Xdiffraction grating that grating RG has. And, a pair of Y liner encoders52 and 53 (see FIG. 6) are configured of the pair of Y heads 75 ya and75 yb that measure the position of fine movement stage WFS1 (or WFS2) inthe Y-axis direction using the Y diffraction grating of grating RG. Themeasurement value of each of X head 75 x and Y heads 75 ya and 75 yb issupplied to main controller 20 (see FIG. 6), and main controller 20measures (computes) the position of fine movement stage WFS1 (or WFS2)in the X-axis direction using (based on) the measurement value of X head75 x, and the position of fine movement stage WFS1 (or WFS2) in theY-axis direction based on the average value of the measurement values ofthe pair of Y head 75 ya and 75 yb. Further, main controller 20 measures(computes) the position in the θz direction (rotational amount aroundthe Z-axis) of fine movement stage WFS1 (or WFS2) using the measurementvalue of each of the pair of Y linear encoders 52 and 53.

In this case, an irradiation point (detection point), on grating RG, ofthe measurement beam irradiated from X head 75 x coincides with theexposure position that is the center of exposure area IA (see FIG. 1) onwafer W. Further, a midpoint of a pair of irradiation points (detectionpoints), on grating RG, of the measurement beams respectively irradiatedfrom the pair of Y heads 75 ya and 75 yb coincides with the irradiationpoint (detection point), on grating RG, of the measurement beamirradiated from X head 75 x. Main controller 20 computes positionalinformation of fine movement stage WFS1 (or WFS2) in the Y-axisdirection based on the average of the measurement values of the two Yheads 75 ya and 75 yb. Therefore, the positional information of finemovement stage WFS1 (or WFS2) in the Y-axis direction is substantiallymeasured at the exposure position that is the center of irradiation area(exposure area) IA of illumination light IL irradiated on wafer W. Morespecifically, the measurement center of X head 75 x and the substantialmeasurement center of the two Y heads 75 ya and 75 yb coincide with theexposure position. Consequently, by using X linear encoder 51 and Ylinear encoders 52 and 53, main controller 20 can perform measurement ofthe positional information within the XY plane (including the rotationalinformation in the θz direction) of fine movement stage WFS1 (or WFS2)directly under (on the back side of) the exposure position at all times.

As each of Z heads 76 a to 76 c, for example, a head of a displacementsensor by an optical method similar to an optical pickup used in a CDdrive device or the like is used. The three Z heads 76 a to 76 c areplaced at the positions corresponding to the respective vertices of anisosceles triangle (or an equilateral triangle). Z heads 76 a to 76 ceach irradiate the lower surface of fine movement stage WFS1 (or WFS2)with a measurement beam parallel to the Z-axis from below, and receivereflected light reflected by the surface of the plate on which gratingRG is formed (or the formation surface of the reflective diffractiongrating). Accordingly, Z heads 76 a to 76 c configure a surface positionmeasuring system 54 (see FIG. 6) that measures the surface position(position in the Z-axis direction) of fine movement stage WFS1 (or WFS2)at the respective irradiation points. The measurement value of each ofthe three Z heads 76 a to 76 c is supplied to main controller 20 (seeFIG. 6).

The center of gravity of the isosceles triangle (or the equilateraltriangle) whose vertices are at the three irradiation points on gratingRG of the measurement beams respectively irradiated from the three Zheads 76 a to 76 c coincides with the exposure position that is thecenter of exposure area IA (see FIG. 1) on wafer W. Consequently, basedon the average value of the measurement values of the three Z heads 76 ato 76 c, main controller 20 can acquire positional information in theZ-axis direction (surface position information) of fine movement stageWFS1 (or WFS2) directly under the exposure position at all times.Further, main controller 20 measures (computes) the rotational amount inthe θx direction and the θy direction, in addition to the position inthe Z-axis direction, of fine movement stage WFS1 (or WFS2) using (basedon) the measurement values of the three Z heads 76 a to 76 c.

Second measurement head group 73 has an X head 77 x that configures an Xliner encoder 55 (see FIG. 6), a pair of Y heads 77 ya and 77 yb thatconfigure a pair of Y linear encoders 56 and 57 (see FIG. 6), and threeZ heads 78 a, 78 b and 78 c that configure a surface position measuringsystem 58 (see FIG. 6). The respective positional relations of the pairof Y heads 77 ya and 77 yb and the three Z heads 78 a to 78 c with Xhead 77 x serving as a reference are similar to the respectivepositional relations described above of the pair of Y heads 75 ya and 75yb and the three Z heads 76 a to 76 c with X head 75 x serving as areference. An irradiation point (detection point), on grating RG, of themeasurement beam irradiated from X head 77 x coincides with thedetection center of primary alignment system AL1. More specifically, themeasurement center of X head 77 x and the substantial measurement centerof the two Y heads 77 ya and 77 yb coincide with the detection center ofprimary alignment system AL1. Consequently, main controller 20 canperform measurement of positional information within the XY plane andsurface position information of fine movement stage WFS2 (or WFS1) atthe detection center of primary alignment system AL1 at all times.

Incidentally, while each of X heads 75 x and 77 x and Y heads 75 ya, 75yb, 77 ya and 77 yb of the embodiment has the light source, thephotodetection system (including the photodetector) and the varioustypes of optical systems (none of which are illustrated) that areunitized and placed inside measurement bar 71, the configuration of theencoder head is not limited thereto. For example, the light source andthe photodetection system can be placed outside the measurement bar. Insuch a case, the optical systems placed inside the measurement bar, andthe light source and the photodetection system are connected to eachother via, for example, an optical fiber or the like. Further, aconfiguration can also be employed in which the encoder head is placedoutside the measurement bar and only a measurement beam is guided to thegrating via an optical fiber placed inside the measurement bar. Further,the rotational information of the wafer in the θz direction can bemeasured using a pair of the X liner encoders (in this case, thereshould be one Y linear encoder). Further, the surface positioninformation of the fine movement stage can be measured using, forexample, an optical interferometer. Further, instead of the respectiveheads of first measurement head group 72 and second measurement headgroup 73, three encoder heads in total, which include at least one XZencoder head whose measurement directions are the X-axis direction andthe Z-axis direction and at least one YZ encoder head whose measurementdirections are the Y-axis direction and the Z-axis direction, can bearranged in the placement similar to that of the X head and the pair ofY heads described earlier.

Further, measurement bar 71 can be divided into a plurality of sections.For example, it is also possible that measurement bar 71 is divided intoa section having first measurement head group 72 and a section havingsecond measurement head group 73, and the respective sections(measurement bars) detect the relative position with main frame BD, with(the measurement reference surface of) main frame BD serving as areference and perform control such that the positional relation isconstant. In this case, a head unit, which includes a plurality ofencoder heads and Z heads (surface position measuring system), isarranged at both ends of the respective sections (measurement bars), andthe positions in the Z-axis direction and the rotational amounts in theθx and θy directions of the respective sections (measurement bars) canbe computed.

When wafer stage WST1 moves between exposure station 200 and measurementstation 300 on surface plate 14A, coarse movement stage positionmeasuring system GSA (see FIG. 6) measures positional information ofcoarse movement stage WCS1 (wafer stage WST1). The configuration ofcoarse movement stage position measuring system 68A is not limited inparticular, and includes an encoder system or an optical interferometersystem (it is also possible to combine the optical interferometer systemand the encoder system). In the case where coarse movement stageposition measuring system 68A includes the encoder system, for example,a configuration can be employed in which the positional information ofcoarse movement stage WCS1 is measured by irradiating a scale (e.g.two-dimensional grating) fixed (or formed) on the upper surface ofcoarse movement stage WCS1 with measurement beams from a plurality ofencoder heads fixed to main frame BD in a suspended state along themovement course of wafer stage WST1 and receiving the diffraction lightof the measurement beams. In the case where coarse movement stagemeasuring system 68A includes the optical interferometer system, aconfiguration can be employed in which the positional information ofwafer stage WST1 is measured by irradiating the side surface of coarsemovement stage WCS1 with measurement beams from an X opticalinterferometer and a Y optical interferometer that have a measurementaxis parallel to the X-axis and a measurement axis parallel to theY-axis respectively and receiving the reflected light of the measurementbeams.

Coarse movement stage position measuring system 68B (see FIG. 6) has theconfiguration similar to coarse movement stage position measuring system68A, and measures positional information of coarse movement stage WCS2(wafer stage WST2) Main controller 20 respectively controls thepositions of coarse movement stages WCS1 and WCS2 (wafer stages WST1 andWST2) by individually controlling coarse movement stage driving systems62A and 62B, based on the measurement values of coarse movement stageposition measuring systems 68A and 68B.

Further, exposure apparatus 100 is also equipped with a relativeposition measuring system 66A and a relative position measuring system66B (see FIG. 6) that measure the relative position between coarsemovement stage WCS1 and fine movement stage WFS1 and the relativeposition between coarse movement stage WCS2 and fine movement stageWFS2, respectively. While the configuration of relative positionmeasuring systems 66A and 66B is not limited in particular, relativeposition measuring systems 66A and 66B can each be configured of, forexample, a gap sensor including a capacitance sensor. In this case, thegap sensor can be configured of, for example, a probe section fixed tocoarse movement stage WCS1 (or WCS2) and a target section fixed to finemovement stage WFS1 (or WFS2). Incidentally, the configuration of therelative position measuring system is not limited thereto, but forexample, the relative position measuring system can be configured using,for example, a liner encoder system, an optical interferometer system orthe like.

FIG. 6 shows a block diagram that shows input/output relations of maincontroller 20 that is configured of a control system of exposureapparatus 100 as the central component and performs overall control ofthe respective components. Main controller 20 includes a workstation (ora microcomputer) and the like, and performs overall control of therespective components of exposure apparatus 100 such as local liquidimmersion device 8, surface plate driving systems 60A and 60B, coarsemovement stage driving systems 62A and 62B, and fine movement stagedriving systems 64A and 64B.

Next, a parallel processing operation using the two wafer stages WST1and WST2 is described with reference to FIGS. 7 to 11. Note that duringthe operation below, main controller 20 controls liquid supply device 5and liquid recovery device 6 as described earlier and a constantquantity of liquid Lq is held directly under tip lens 191 of projectionoptical system PL, and thereby a liquid immersion area is formed at alltimes.

FIG. 7 shows a state where exposure by a step-and-scan method isperformed on wafer W mounted on fine movement stage WFS1 of wafer stageWST1 in exposure station 200, and in parallel with this exposure, waferexchange is performed between a wafer carrier mechanism (notillustrated) and fine movement stage WFS2 of wafer stage WST2 at thesecond loading position.

Main controller 20 performs the exposure operation by a step-and-scanmethod by repeating an inter-shot movement (stepping between shots)operation of moving wafer stage WST1 to a scanning starting position(acceleration starting position) for exposure of each shot area on waferW, based on the results of wafer alignment (e.g. information obtained byconverting an arrangement coordinate of each shot area on wafer Wobtained by an Enhanced Global Alignment (EGA) into a coordinate withthe second fiducial mark on measurement plate FM1 serving as areference) and reticle alignment and the like that have been performedbeforehand, and a scanning exposure operation of transferring a patternformed on reticle R onto each shot area on wafer W by a scanningexposure method. During this step-and-scan operation, surface plates 14Aand 14B exert the function as the countermasses, as describedpreviously, according to movement of wafer stage WST1, for example, inthe Y-axis direction during scanning exposure. Further, main controller20 gives the initial velocity to coarse movement stage WCS1 when drivingfine movement stage WFS1 in the X-axis direction for the steppingoperation between shots, and thereby coarse movement stage WCS1functions as a local countermass with respect to fine movement stageWFS1. Consequently, the movement of wafer stage WST1 (coarse movementstage WCS1 and fine movement stage WFS1) does not cause vibration ofsurface plates 14A and 14B and does not adversely affect wafer stageWST2.

The exposure operations described above are performed in a state whereliquid Lq is held in the space between tip lens 191 and wafer W (wafer Wand plate 82 depending on the position of a shot area), or morespecifically, by liquid immersion exposure.

In exposure apparatus 100 of the embodiment, during a series of theexposure operations described above, main controller 20 measures theposition of fine movement stage WFS1 using first measurement head group72 of fine movement stage position measuring system 70 and controls theposition of fine movement stage WFS1 (wafer W) based on this measurementresult.

The wafer exchange is performed by unloading a wafer that has beenexposed from fine movement stage WFS2 and loading a new wafer onto finemovement stage WFS2 by the wafer carrier mechanism that is notillustrated, when fine movement stage WFS2 is located at the secondloading position. In this case, the second loading position is aposition where the wafer exchange is performed on wafer stage WST2, andin the embodiment, the second loading position is to be set at theposition where fine movement stage WFS2 (wafer stage WST2) is locatedsuch that measurement plate FM2 is positioned directly under primaryalignment system AL1.

During the wafer exchange described above, and after the wafer exchange,while wafer stage WST2 stops at the second loading position, maincontroller 20 executes reset (resetting of the origin) of secondmeasurement head group 73 of fine movement stage position measuringsystem 70, or more specifically, encoders 55, 56 and 57 (and surfaceposition measuring system 58), prior to start of wafer alignment (andthe other pre-processing measurements) with respect to the new wafer W.

When the wafer exchange (loading of the new wafer W) and the reset ofencoders 55, 56 and 57 (and surface position measuring system 58) havebeen completed, main controller 20 detects the second fiducial mark onmeasurement plate FM2 using primary alignment system AL1. Then, maincontroller 20 detects the position of the second fiducial mark with theindex center of primary alignment system AL1 serving as a reference, andbased on the detection result and the result of position measurement offine movement stage WFS2 by encoders 55, 56 and 57 at the time of thedetection, computes the position coordinate of the second fiducial markin an orthogonal coordinate system (alignment coordinate system) withreference axis La and reference axis LV serving as coordinate axes.

Next, main controller 20 performs the EGA while measuring the positioncoordinate of fine movement stage WFS2 (wafer stage WST2) in thealignment coordinate system using encoders 55, 56 and 57 (see FIG. 8).To be more specific, as disclosed in, for example, U.S. PatentApplication Publication No, 2008/0088843 and the like, main controller20 moves wafer stage WST2, or more specifically, coarse movement stageWCS2 that supports fine movement stage WFS2 in, for example, the Y-axisdirection, and sets the position of fine movement stage WFS2 at aplurality of positions in the movement course, and at each positionsetting, detects the position coordinates, in the alignment coordinatesystem, of alignment marks at alignment shot areas (sample shot areas)using at least one of alignment systems AL1 and AL2 ₂ and AL2 ₄. FIG. 8shows a state of wafer stage WST2 when the detection of the positioncoordinates of the alignment marks in the alignment coordinate system isperformed.

In this case, in conjunction with the movement operation of wafer stageWST2 in the Y-axis direction described above, alignment systems AL1 andAL2 ₂ to AL2 ₄ respectively detect a plurality of alignment marks(sample marks) disposed along the X-axis direction that are sequentiallyplaced within the detection areas (e.g. corresponding to the irradiationareas of detection light). Therefore, on the measurement of thealignment marks described above, wafer stage WST2 is not driven in theX-axis direction.

Then, based on the position coordinates of the plurality of alignmentmarks arranged at the sample shot areas on wafer W and the designposition coordinates, main controller 20 executes statisticalcomputation (EGA computation) disclosed in, for example, U.S. Pat. No.4,780,617 and the like, and computes the position coordinates(arrangement coordinates) of the plurality of shot areas in thealignment coordinate system.

Further, in exposure apparatus 100 of the embodiment, since measurementstation 300 and exposure station 200 are spaced apart, main controller20 subtracts the position coordinate of the second fiducial mark thathas previously been detected from the position coordinate of each of theshot areas on wafer W that has been obtained as a result of the waferalignment, thereby obtaining the position coordinates of the pluralityof shot areas on wafer W with the position of the second fiducial markserving as the origin.

Normally, the above-described wafer exchange and wafer alignmentsequence is completed earlier than the exposure sequence. Therefore,when the wafer alignment has been completed, main controller 20 driveswafer stage WST2 in the +X direction to move wafer stage WST2 to apredetermined standby position on surface plate 14B. In this case, whenwafer stage WST2 is driven in the +X direction, fine movement stage WFSgoes out of a measurable range of fine movement stage position measuringsystem 70 (i.e. the respective measurement beams irradiated from secondmeasurement head group 73 move off from grating RG). Therefore, based onthe measurement values of fine movement stage position measuring system70 (encoders 55, 56 and 57) and the measurement values of relativeposition measuring system 66B, main controller 20 obtains the positionof coarse movement stage WCS2, and afterward, controls the position ofwafer stage WST2 based on the measurement values of coarse movementstage position measuring system 68B. More specifically, positionmeasurement of wafer stage WST2 within the XY plane is switched from themeasurement using encoders 55, 56 and 57 to the measurement using coarsemovement stage position measuring system 68B. Then, main controller 20makes wafer stage WST2 wait at the predetermined standby positiondescribed above until exposure on wafer W on fine movement stage WFS1 iscompleted.

When the exposure on wafer W on fine movement stage WFS1 has beencompleted, main controller 20 starts to drive wafer stages WST1 and WST2severally toward a right-side scrum position shown in FIG. 10. Whenwafer stage WST1 is driven in the −X direction toward the right-sidescrum position, fine movement stage WFS1 goes out of the measurablerange of fine movement stage position measuring system 70 (encoders 51,52 and 53 and surface position measuring system 54) (i.e. themeasurement beams irradiated from first measurement head group 72 moveoff from grating RG). Therefore, based on the measurement values of finemovement stage position measuring system 70 (encoders 51, 52 and 53) andthe measurement values of relative position measuring system 66A, maincontroller 20 obtains the position of coarse movement stage WCS1, andafterward, controls the position of wafer stage WST1 based on themeasurement values of coarse movement stage position measuring system68A. More specifically, main controller 20 switches position measurementof wafer stage WST1 within the XY plane from the measurement usingencoders 51, 52 and 53 to the measurement using coarse movement stageposition measuring system 68A. During this operation, main controller 20measures the position of wafer stage WST2 using coarse movement stageposition measuring system 68B, and based on the measurement result,drives wafer stage WST2 in the +Y direction (see an outlined arrow inFIG. 9) on surface plate 14B, as shown in FIG. 9. Owing to the action ofa reaction force of this drive force of wafer stage WST2, surface plate14B functions as the countermass.

Further, in parallel with the movement of wafer stages WST1 and WST2toward the right-side scrum position described above, main controller 20drives fine movement stage WFS1 in the +X direction based on themeasurement values of relative position measuring system 66A and causesfine movement stage WFS1 to be in proximity to or in contact with coarsemovement stage WCS1, and also drives fine movement stage WFS2 in the −Xdirection based on the measurement values of relative position measuringsystem 66B and causes fine movement stage WFS2 to be in proximity to orin contact with coarse movement stage WCS2.

Then, in a state where both wafer stages WST1 and WST2 have moved to theright-side scrum position, wafer stage WST1 and wafer stage WST2 go intoa scrum state of being in proximity or in contact in the X-axisdirection, as shown in FIG. 10. Simultaneously with this state, finemovement stage WFS1 and coarse movement stage WCS1 go into a scrumstate, and coarse movement stage WCS2 and fine movement stage WFS2 gointo a scrum state. Then, the upper surfaces of fine movement stageWFS1, coupling member 92 b of coarse movement stage WCS1, couplingmember 92 b of coarse movement stage WCS2 and fine movement stage WFS2form a fully flat surface that is apparently integrated.

As wafer stages WST1 and WST2 move in the −X direction while the threescrum states described above are kept, the liquid immersion area (liquidLq) formed between tip lens 191 and fine movement stage WFS1sequentially moves onto fine movement stage WFS1, coupling member 92 bof coarse movement stage WCS1, coupling member 92 b of coarse movementstage WCS2, and fine movement stage WFS2. FIG. 10 shows a state justbefore starting the movement of the liquid immersion area (liquid Lq).Note that in the case where wafer stage WST1 and wafer stage WST2 aredriven while the above-described three scrum states are kept, it ispreferable that a gap (clearance) between wafer stage WST1 and waferstage WST2, a gap (clearance) between fine movement stage WFS1 andcoarse movement stage WCS1 and a gap (clearance) between coarse movementstage WCS2 and fine movement stage WFS2 are set such that leakage ofliquid Lq is prevented or restrained. In this case, the proximityincludes the case where the gap (clearance) between the two members inthe scrum state is zero, or more specifically, the case where both themembers are in contact.

When the movement of the liquid immersion area (liquid Lq) onto finemovement stage WFS2 has been completed, wafer stage WST1 has moved ontosurface plate 14A. Then, main controller 20 moves wafer stage WST1 inthe −Y direction and further in the +X direction on surface plate 14A,while measuring the position of wafer stage WST1 using coarse movementstage position measuring system 68A, so as to move wafer stage WST1 tothe first loading position shown in FIG. 11. In this case, on themovement of wafer stage WST1 in the −Y direction, surface plate 14Afunctions as the countermass owing to the action of a reaction force ofthe drive force, Further, when wafer stage WST1 moves in the +Xdirection, surface plate 14A can be made to function as the countermassowing to the action of a reaction force of the drive force.

After wafer stage WST1 has reached the first loading position, maincontroller 20 switches position measurement of wafer stage WST1 withinthe XY plane from the measurement using coarse movement stage positionmeasuring system 68A to the measurement using encoders 55, 56 and 57.

In parallel with the movement of wafer stage WST1 described above, maincontroller 20 drives wafer stage WST2 and sets the position ofmeasurement plate FM2 at a position directly under projection opticalsystem PL. Prior to this operation, main controller 20 has switchedposition measurement of wafer stage WST2 within the XY plane from themeasurement using coarse movement stage position measuring system 68B tothe measurement using encoders 51, 52 and 53. Then, the pair of firstfiducial marks on measurement plate FM2 are detected using reticlealignment systems RA₁ and RA₂ and the relative position of projectedimages, on the wafer, of the reticle alignment marks on reticle R thatcorrespond to the first fiducial marks are detected. Note that thisdetection is performed via projection optical system PL and liquid Lqthat forms the liquid immersion area.

Based on the relative positional information detected as above and thepositional information of each of the shot areas on wafer W with thesecond fiducial mark on fine movement stage WFS2 serving as a referencethat has been previously obtained, main controller 20 computes therelative positional relation between the projection position of thepattern of reticle R (the projection center of projection optical systemPL) and each of the shot areas on wafer W mounted on fine movement stageWFS2. While controlling the position of fine movement stage WFS2 (waferstage WST2) based on the computation results, main controller 20transfers the pattern of reticle R onto each shot area on wafer Wmounted on fine movement stage WFS2 by a step-and-scan method, which issimilar to the case of wafer W mounted on fine movement stage WFS1described earlier. FIG. 11 shows a state where the pattern of reticle Ris transferred onto each shot area on wafer W in this manner.

In parallel with the above-described exposure operation on wafer W onfine movement stage WFS2, main controller 20 performs the wafer exchangebetween the wafer carrier mechanism not illustrated) and wafer stageWST1 at the first loading position and mounts a new wafer W on finemovement stage WFS1. In this case, the first loading position is aposition where the wafer exchange is performed on wafer stage WST1, andin the embodiment, the first loading position is to be set at theposition where fine movement stage WFS1 (wafer stage WST1) is locatedsuch that measurement plate FM1 is positioned directly under primaryalignment system AL1.

Then, main controller 20 detects the second fiducial mark on measurementplate FM1 using primary alignment system AL1. Note that, prior to thedetection of the second fiducial mark, main controller 20 executes reset(resetting of the origin) of second measurement head group 73 of finemovement stage position measuring system 70, or more specifically,encoders 55, 56 and 57 (and surface position measuring system 58), in astate where wafer stage WST1 is located at the first loading position.After that, main controller 20 performs wafer alignment (EGA) usingalignment systems AL1 and AL2 ₁ to AL2 ₄, which is similar to theabove-described one, with respect to wafer W on fine movement stageWFS1, while controlling the position of wafer stage WST1.

When the wafer alignment (EGA) with respect to wafer W on fine movementstage WFS1 has been completed and also the exposure on wafer W on finemovement stage WFS2 has been completed, main controller 20 drives waferstages WST1 and WST2 toward a left-side scrum position. This left-sidescrum position indicates a positional relation in which wafer stagesWST1 and WST2 are located at positions that are bilaterally symmetricwith the positions of the wafer stages in the right-side scrum positionshown in FIG. 10, with respect to reference axis LV described above.Measurement of the position of wafer stage WST1 during the drive towardthe left-side scrum position is performed in a similar procedure to thatof the position measurement of wafer stage WST2 described earlier.

At this left-side scrum position as well, wafer stage WST1 and waferstage WST2 go into the scrum state described earlier, and concurrentlywith this state, fine movement stage WFS1 and coarse movement stage WCS1go into the scrum state and coarse movement stage WCS2 and fine movementstage WFS2 go into the scrum state. Then, the upper surfaces of finemovement stage WFS1, coupling member 92 b of coarse movement stage WCS1,coupling member 92 b of coarse movement stage WCS2 and fine movementstage WFS2 form a fully flat surface that is apparently integrated.

Main controller 20 drives wafer stages WST1 and WST2 in the +X directionthat is reverse to the previous direction, while keeping the three scrumstates described above. According this drive, the liquid immersion area(liquid Lq) formed between tip lens 191 and fine movement stage WFS2sequentially moves onto fine movement stage WFS2, coupling member 92 bof coarse movement stage WCS2, coupling member 92 h of coarse movementstage WCS1 and fine movement stage WFS1, which is reverse to thepreviously described order. As a matter of course, also when the waferstages are moved while the scrum states are kept, the positionmeasurement of wafer stages WST1 and WST2 is performed, similarly to thepreviously described case. When the movement of the liquid immersionarea (liquid Lq) has been completed, main controller 20 starts exposureon wafer W on wafer stage WST1 in the procedure similar to thepreviously described procedure. In parallel with this exposureoperation, main controller 20 drives wafer stage WST2 toward the secondloading position in a manner similar to the previously described manner,exchanges wafer W that has been exposed on wafer stage WST2 with a newwafer W, and executes the wafer alignment with respect to the new waferW.

After that, main controller 20 repeatedly executes the parallelprocessing operations using wafer stages WST1 and WST2 described above.

As described above, in exposure apparatus 100 of the embodiment, duringthe exposure operation and during the wafer alignment (mainly, duringthe measurement of the alignment marks), first measurement head group 72and second measurement head group 73 fixed to measurement bar 71 arerespectively used in the measurement of the positional information (thepositional information within the XY plane and the surface positioninformation) of fine movement stage WFS1 (or WFS2) that holds wafer W.And, since encoder heads 75 x, 75 ya and 75 yb and Z heads 76 a to 76 cthat configure first measurement head group 72, and encoder heads 77 x,77 ya and 77 yb and Z heads 78 a to 78 c that configure secondmeasurement head group 73 can respectively irradiate grating RG placedon the bottom surface of fine movement stage WFS1 (or WFS2) withmeasurement beams from directly below at the shortest distance,measurement error caused by temperature fluctuation of the surroundingatmosphere of wafer stage WST1 or WST2, e.g., air fluctuation isreduced, and high-precision measurement of the positional information offine movement stage WFS can be performed.

Further, first measurement head group 72 measures the positionalinformation within the XY plane and the surface position information offine movement stage WFS1 (or WFS2) at the point that substantiallycoincides with the exposure position that is the center of exposure areaIA on wafer W, and second measurement head group 73 measures thepositional information within the XY plane and the surface positioninformation of fine movement stage WFS2 (or WFS1) at the point thatsubstantially coincides with the center of the detection area of primaryalignment system AL1. Consequently, occurrence of the so-called Abbeerror caused by the positional error within the XY plane between themeasurement point and the exposure position is restrained, and also inthis regard, high-precision measurement of the positional information offine movement stage WFS1 of WFS2 can be performed.

Further, since measurement bar 71 that has first measurement head group72 and second measurement head group 73 is fixed in a suspended state tomain frame BD to which barrel 40 is fixed, it becomes possible toperform high-precision position control of wafer stage WST1 (or WST2)with the optical axis of projection optical system PL held by barrel 40serving as a reference. Further, since measurement bar 71 is in amechanically noncontact state with the members (e.g. surface plates 14Aand 14B, base board 14, and the like) other than main frame BD,vibration or the like generated when surface plates 14A and 14B, waferstages WST1 and WST2, and the like are driven does not travel.Consequently, it becomes possible to perform high-precision measurementof the positional information of wafer stage WST (or WST2) by usingfirst measurement head group 72 and second measurement head group 73.

Further, in wafer stages WST1 and WST2 in the embodiment, since coarsemovement stage WCS1 (or WCS2) is placed on the periphery of finemovement stage WFS1 (or WFS2), wafer stages WST1 and WST2 can be reducedin size in the height direction (Z-axis direction), compared with awafer stage that has a coarse/fine movement configuration in which afine movement stage is mounted on a coarse movement stage. Therefore,the distance in the Z-axis direction between the point of action of thethrust of the planar motors that configure coarse movement stage drivingsystems 62A and 62B (i.e. the point between the bottom surface of coarsemovement stage WCS1 (WCS2) and the upper surfaces of surface plates 14Aand 14B) and the center of gravity of wafer stages WST1 and WST2 can bedecreased, and accordingly, the pitching moment (or the rolling moment)generated when wafer stages WST1 and WTS2 are driven can be reduced.Consequently, the operations of wafer stages WST1 and WST2 becomestable.

Further, in exposure apparatus 100 of the embodiment, the surface platethat forms the guide surface used when wafer stages WST1 and WST2 movealong the XY plane is configured of the two surface plates 14A and 14Bso as to correspond to the two wafer stages WST1 and WST2. These twosurface plates 14A and 14B independently function as the countermasseswhen wafer stages WST1 and WST2 are driven by the planar motors (coarsemovement stage driving systems 62A and 62B), and therefore, for example,even when wafer stage WST1 and wafer stage WST2 are respectively drivenin directions opposite to each other in the Y-axis direction on surfaceplates 14A and 14B, surface plates 14A and 14B can individually cancelthe reaction forces respectively acting on the surface plates.

Incidentally, in the embodiment above, while the case has been describedwhere the coarse/fine movement stage composed of the coarse movementstage that moves in the XY two-dimensional directions within apredetermined range on the surface plate and the fine movement stagethat is finely driven on the coarse movement stage is used as a waferstage, this is not intended to be limiting, and the variousmodifications can be applied to the configuration of the wafer stage.FIG. 12A shows a plan view of a modified example of the wafer stage ofthe embodiment above, and FIG. 12B shows a cross-sectional view takenalong the B-B line of FIG. 12A. In a wafer stage WST3 of the modifiedexample shown in FIG. 12A, a member 180 (a tabular member that holdswafer W on its upper surface and has grating RG on its lower surface)that corresponds to the fine movement stage in the embodiment above isfixed integrally with a member 190 having a rectangular frame shape in aplanar view that corresponds to the coarse movement stage, and the shapeas a whole is formed into a tabular shape. Wafer stage WST3 has magneticunits 196 a and 196 b on its end on the side and its end the −Y side,respectively. Wafer stage WST3 is driven along the XY plane on thesurface plate by a planar motor configured of magnetic units 196 a and196 b and coil units (the illustration is omitted) of the surface platethat is capable of generating the thrust in the directions of sixdegrees of freedom (i.e. the planar motor functions as a drive systemused in both coarse and fine movement). Incidentally, also in this case,the planar motor can be of the moving magnet type or of the moving coiltype, and either of them can be applied.

Further, while the exposure apparatus of the embodiment above has thetwo surface plates corresponding to the two wafer stages, the number ofthe surface plates is not limited thereto, and one surface plate orthree or more surface plates can be employed. Further, the number of thewafer stages is not limited to two, but one wafer stage or three or morewafer stages can be employed, and a measurement stage, which has anaerial image measuring instrument, an uneven illuminance measuringinstrument, an illuminance monitor, a wavefront aberration measuringinstrument and the like, can be placed on the surface plate, which isdisclosed in, for example, U.S. Patent Application Publication No.2007/0201010.

Further, the position of the border line that separates the surfaceplate or the base member into a plurality of sections is not limited tothe position as in the embodiment above. While the border line is set toa line that includes reference axis LV and intersects optical axis AX inthe embodiment above, the border line can be set at another position,for example, in the case where, if the boundary is located in theexposure station, the thrust of the planar motor at the portion wherethe boundary is located weakens.

Further, the mid portion (which can be arranged at a plurality ofpositions) in the longitudinal direction of measurement bar 71 can besupported on the base board by an empty-weight canceller as disclosedin, for example, U.S. Patent Application Publication No. 2007/0201010.

Further, the motor to drive surface plates 14A and 14B on base board 12is not limited to the planar motor by the electromagnetic force (Lorentzforce) drive method, but for example, can be a planar motor (or a linearmotor) by a variable magnetoresistance drive method. Further, the motoris not limited to the planar motor, but can be a voice coil motor thatincludes a mover fixed to the side surface of the surface plate and astator fixed to the base board. Further, the surface plates can besupported on the base board via the empty-weight canceller as disclosedin, for example, U.S. Patent Application Publication No. 2007/0201010and the like. Further, the drive directions of the surface plates arenot limited to the directions of three degrees of freedom, but forexample, can be the directions of six degrees of freedom, only theY-axis direction, or only the XY two-axial directions. In this case, thesurface plates can be levitated above the base board by static gasbearings (e.g. air bearings) or the like. Further, in the case where themovement direction of the surface plates can be only the Y-axisdirection, the surface plates can be mounted on, for example, a Y guidemember arranged extending in the Y-axis direction so as to be movable inthe Y-axis direction.

Further, in the embodiment above, while the grating is placed on thelower surface of the fine movement stage, i.e., the surface that isopposed to the upper surface of the surface plate, this is not intendedto be limiting, and the main section of the fine movement stage is madeup of a solid member that can transmit light, and the grating can beplaced on the upper surface of the main section. In this case, since thedistance between the wafer and the grating is closer compared with theembodiment above, the Abbe error, which is caused by the difference inthe Z-axis direction between the surface subject to exposure of thewafer that includes the exposure point and the reference surface (theplacement surface of the grating) of position measurement of the finemovement stage by encoders 51, 52 and 53, can be reduced. Further, thegrating can be formed on the back surface of the wafer holder. In thiscase, even if the wafer holder expands or the attachment position withrespect to the fine movement stage shifts during exposure, the positionof the wafer holder (wafer) can be measured according to the expansionor the shift.

Further, in the embodiment above, while the case has been described asan example where the encoder system is equipped with the X head and thepair of Y heads, this is not intended to be limiting, and for example,one or two two-dimensional head(s) (2D head (s)) whose measurementdirections are the two directions that are the X-axis direction and theY-axis direction can be placed inside the measurement bar. In the caseof arranging the two 2D heads, their detection points can be set at thetwo points that are spaced apart in the X-axis direction at the samedistance from the exposure position as the center, on the grating.Further, in the embodiment above, while the number of heads per headgroup is the one X head and the two Y heads, the number of the heads canbe further be increased. Moreover, first measurement head group 72 onthe exposure station 200 side can further have a plurality of headgroups. For example, on each of the sides (the four directions that arethe +X, +Y, −X and −Y directions) on the periphery of the head groupplaced at the position corresponding to the exposure position (a shotarea being exposed on wafer W), another head group can be arranged. And,the position of the fine movement stage (wafer W) just before exposureof the shot area can be measured in a so-called read-ahead manner.Further, the configuration of the encoder system that configures finemovement stage position measuring system 70 is not limited to the one inthe embodiment above and an arbitrary configuration can be employed. Forexample, a 3D head can also be used that is capable of measuring thepositional information in each direction of the X-axis, the Y-axis andthe Z-axis.

Further, in the embodiment above, the measurement beams emitted from theencoder heads and the measurement beams emitted from the Z heads areirradiated on the gratings of the fine movement stages via a gap betweenthe two surface plates or the light-transmitting section formed at eachof the surface plates. In this case, as the light-transmitting section,holes each of which is slightly larger than a beam diameter of each ofthe measurement beams are formed at each of surface plates 14A and 14Btaking the movement range of surface plate 14A or 14B as the countermassinto consideration, and the measurement beams can be made to passthrough these multiple opening sections. Further, for example, it isalso possible that pencil-type heads are used as the respective encoderheads and the respective Z heads, and opening sections in which theseheads are inserted are formed at each of the surface plates.

Incidentally, in the embodiment above, the case has been described as anexample where according to employment of the planar motors as coarsemovement stage driving systems 62A and 62B that drive wafer stages WST1and WST2, the guide surface (the surface that generates the force in theZ-axis direction) used on the movement of wafer stages WST1 and WST2along the XY plane is formed by surface plates 14A and 14B that have thestator sections of the planar motors. However, the embodiment above isnot limited thereto. Further, in the embodiment above, while themeasurement surface (grating RG) is arranged on fine movement stagesWFS1 and WFS2 and first measurement head group 72 (and secondmeasurement head group 73) composed of the encoder heads (and the Zheads) is arranged at measurement bar 71, the embodiment above is notlimited thereto. More specifically, reversely to the above-describedcase, the encoder heads (and the Z heads) can be arranged at finemovement stage WFS1 and the measurement surface (grating RG) can beformed on the measurement bar 71 side. Such a reverse placement can beapplied to a stage device that has a configuration in which a magneticlevitated stage is combined with a so-called H-type stage, which isemployed in, for example, an electron beam exposure apparatus, an EUVexposure apparatus or the like. In this stage device, since a stage issupported by a guide bar, a scale bar (which corresponds to themeasurement bar on the surface of which a diffraction grating is formed)is placed below the stage so as to be opposed to the stage, and at leasta part (such as an optical system) of an encoder head is placed on thelower surface of the stage that is opposed to the scale bar. In thiscase, the guide bar configures the guide surface forming member. As amatter of course, another configuration can also be employed. The placewhere grating RG is arranged on the measurement bar 71 side can be, forexample, measurement bar 71, or a plate of a nonmagnetic material or thelike that is arranged on the entire surface or at least one surface onsurface plate 14A (14B).

Incidentally, in the embodiment above, since measurement bar 71 isintegrally fixed to main frame BD, there is a possibility that twist orthe like occurs in measurement bar 71 owing to inner stress (includingthermal stress) and the relative position between measurement bar 71 andmain frame BD varies. Therefore, as the countermeasure taken in such ascase, it is also possible that the position of measurement bar 71 (therelative position with respect to main frame BD, or the variation of theposition with respect to a reference position) is measured, and theposition of measurement bar 71 is finely adjusted by an actuator or thelike, or the measurement result is corrected.

Further, in the embodiment above, while the case has been describedwhere measurement bar 71 and main frame BD are integrated, this is notintended to be limiting, and measurement bar 71 and main frame BD canphysically be separated. In such a case, a measurement device (e.g. anencoder and/or an interferometer, or the like) that measures theposition (or displacement) of measurement bar 71 with respect to mainframe BD (or a reference position), and an actuator or the like thatadjusts the position of measurement bar 71 should be arranged, and basedon the measurement result of the measurement device, main controller 20and/or another controller should maintain the positional relationbetween main frame BD (and projection optical system PL) and measurementbar 71 in a predetermined relation (e.g. constant).

Further, a measurement system (sensor) that measures variation ofmeasurement bar 71 with an optical method, a temperature sensor, apressure sensor, an acceleration sensor for vibration measurement, andthe like can be arranged at measurement bar 71. Or, a distortion sensor(distortion gauge), or a displacement sensor and the like to measurevariation of measurement bar 71 can be arranged. Then, it is alsopossible to correct the positional information obtained by fine movementstage position measuring system 70 and/or coarse movement stage positionmeasuring systems 68A and 68B, using the values obtained by thesesensors.

Further, in the embodiment above, the case has been described where theliquid immersion area (liquid Lq) is constantly maintained belowprojection optical system PL by delivering the liquid immersion area(liquid Lq) between fine movement stage WFS1 and fine movement stageWFS2 via coupling members 92 b that coarse movement stages WCS1 and WCS2are respectively equipped with. However, this is not intended to belimiting, and it is also possible that the liquid immersion area (liquidLq) is constantly maintained below projection optical system PL bymoving a shutter member (not illustrated) having a configuration similarto the one disclosed in, for example, the third embodiment of U.S.Patent Application Publication No. 2004/0211920, to below projectionoptical system PL in exchange of wafer stages WST1 and WST2.

Further, in the embodiment above, while the case has been describedwhere the present invention is applied to stage device (wafer stages) 50of the exposure apparatus, this is not intended to be limiting, and thepresent invention can also be applied to reticle stage RST.

Incidentally, in the embodiment above, grating RG can be covered with aprotective member, e.g. a cover glass, so as to be protected. The coverglass can be arranged to cover the substantially entire surface of thelower surface of main section 80, or can be arranged to cover only apart of the lower surface of main section 80 that includes grating RG.Further, while a plate-shaped protective member is desirable because thethickness enough to protect grating RG is required, a thin film-shapedprotective member can also be used depending on the material.

Besides, it is also possible that a transparent plate, on one surface ofwhich grating RG is fixed or formed, has the other surface that isplaced in contact with or in proximity to the back surface of the waferholder and a protective member (cover glass) is arranged on the onesurface side of the transparent plate, or the one surface of thetransparent plate on which grating RG is fixed or formed is placed incontact with or in proximity to the back surface of the wafer holderwithout arranging the protective member (cover glass). Especially in theformer case, grating RG can be fixed or formed on an opaque member suchas ceramics instead of the transparent plate, or grating RG can be fixedor formed on the back surface of the wafer holder. In the latter case,even if the wafer holder expands or the attachment position with respectto the fine movement stage shifts during exposure, the position of thewafer holder (wafer) can be measured according to the expansion or theshift. Or, it is also possible that the wafer holder and grating RG aremerely held by the conventional fine movement stage. Further, it is alsopossible that the wafer holder is formed by a solid glass member, andgrating RG is placed on the upper surface (wafer mounting surface) ofthe glass member.

Incidentally, in the embodiment above, while the case has been describedas an example where the wafer stage is a coarse/fine movement stage thatis a combination of the coarse movement stage and the fine movementstage, this is not intended to be limiting. Further, in the embodimentabove, while fine movement stages WFS1 and WFS2 can be driven in all thedirections of six degrees of freedom, this is not intended to belimiting, and the fine movement stages should be moved at least withinthe two-dimensional plane parallel to the XY plane. Moreover, finemovement stages WFS1 and WFS2 can be supported in a contact manner bycoarse movement stages WCS1 and WCS2. Consequently, the fine movementstage driving system to drive fine movement stage WFS1 or WFS2 withrespect to coarse movement stage WCS1 car WCS2 can be a combination of arotary motor and a ball screw (or a feed screw).

Incidentally, the fine movement stage position measuring system can beconfigured such that the position measurement can be performed in theentire area of the movement range of the wafer stages. In such a case,the coarse movement stage position measuring systems become unnecessary.

Incidentally, the wafer used in the exposure apparatus of the embodimentabove can be any one of wafers with various sizes, such as a 450-mmwafer or a 300-mm wafer.

Incidentally, in the embodiment above, while the case has beendescribed, where the exposure apparatus is the liquid immersion typeexposure apparatus, this is not intended to be limiting, and theembodiment above can suitably be applied to a dry type exposureapparatus that performs exposure of wafer W without liquid (water).

Incidentally, in the embodiment above, while the case has been describedwhere the exposure apparatus is a scanning stepper, this is not intendedto be limiting, and the embodiment above can also be applied to a staticexposure apparatus such as a stepper. Even in the stepper or the like,occurrence of position measurement error caused by air fluctuation canbe reduced to almost zero by measuring the position of a stage on whichan object that is subject to exposure is mounted using an encoder.Therefore, it becomes possible to set the position of the stage withhigh precision based on the measurement values of the encoder, and as aconsequence, high-precision transfer of a reticle pattern onto theobject can be performed. Further, the embodiment above can also beapplied to a reduced projection exposure apparatus by a step-and-stitchmethod that synthesizes a shot area and a shot area.

Further, the magnification of the projection optical system in theexposure apparatus in the embodiment above is not only a reductionsystem, but also can be either an equal magnifying system or amagnifying system, and the projection optical system is not only adioptric system, but also can be either a catoptric system or acatadioptric system, and in addition, the projected image can be eitheran inverted image or an erected image.

Further, illumination light IL is not limited to ArF excimer laser light(with a wavelength of 193 nm), but can be ultraviolet light such as KrFexcimer laser light (with a wavelength of 248 nm), or vacuum ultravioletlight such as F₂ laser light (with a wavelength of 157 nm). As disclosedin, for example, U.S. Pat. No. 7,023,610, a harmonic wave, which isobtained by amplifying a single-wavelength laser beam in the infrared orvisible range emitted by a DFB semiconductor laser or fiber laser with afiber amplifier doped with, for example, erbium (or both erbium andytteribium), and by converting the wavelength into ultraviolet lightusing a nonlinear optical crystal, can also be used as vacuumultraviolet light.

Further, in the embodiment above, illumination light IL of the exposureapparatus is not limited to the light having a wavelength more than orequal to 100 nm, and it is needless to say that the light having awavelength less than 100 nm can be used. For example, the embodimentabove can be applied to an EUV (Extreme Ultraviolet) exposure apparatusthat uses an EUV light in a soft X-ray range (e.g. a wavelength rangefrom 5 to 15 nm). In addition, the embodiment above can also be appliedto an exposure apparatus that uses charged particle beams such as anelectron beam or an ion beam.

Further, in the embodiment above, a light transmissive type mask(reticle) is used, which is obtained by forming a predeterminedlight-shielding pattern (or a phase pattern or a light-attenuationpattern) on a light-transmitting substrate, but instead of this reticle,as disclosed in, for example, U.S. Pat. No. 6,778,257, an electron mask(which is also called a variable shaped mask, an active mask or an imagegenerator, and includes, for example, a DMD (Digital Micromirror Device)that is a type of a non-emission type image display element (spatiallight modulator) or the like) on which a light-transmitting pattern, areflection pattern, or an emission pattern is formed according toelectronic data of the pattern that is to be exposed can also be used.In the case of using such a variable shaped mask, a stage on which awafer, a glass plate or the like is mounted is scanned relative to thevariable shaped mask, and therefore the equivalent effect to theembodiment above can be obtained by measuring the position of this stageusing an encoder system.

Further, as disclosed in, for example, PCT International Publication No.2001/035168, the embodiment above can also be applied to an exposureapparatus (a lithography system) in which line-and-space patterns areformed on wafer W by forming interference fringes on wafer W.

Moreover, the embodiment above can also be applied to an exposureapparatus that synthesizes two reticle patterns on a wafer via aprojection optical system and substantially simultaneously performsdouble exposure of one shot area on the wafer by one scanning exposure,as disclosed in, for example, U.S. Pat. No. 6,611,316.

Incidentally, an object on which a pattern is to be formed (an objectsubject to exposure on which an energy beam is irradiated) in theembodiment above is not limited to a wafer, but may be another objectsuch as a glass plate, a ceramic substrate, a film member, or a maskblank.

The usage of the exposure apparatus is not limited to the exposureapparatus used for manufacturing semiconductor devices, but the presentinvention can be widely applied also to, for example, an exposureapparatus for manufacturing liquid crystal display elements in which aliquid crystal display element pattern is transferred onto a rectangularglass plate, and to an exposure apparatus for manufacturing organic EL,thin-film magnetic heads, imaging devices (such as CCDs),micromachines,DNA chips or the like. Further, the embodiment above can also be appliedto an exposure apparatus that transfers a circuit pattern onto a glasssubstrate, a silicon wafer or the like not only when producingmicrodevices such as semiconductor devices, but also when producing areticle or a mask used in an exposure apparatus such as an opticalexposure apparatus, an EUV exposure apparatus, an X-ray exposureapparatus, and an electron beam exposure apparatus.

Incidentally, the disclosures of all publications, the PCT InternationalPublications, the U.S. Patent Application Publications and the U.S.Patents that are cited in the description so far related to exposureapparatuses and the like are each incorporated herein by reference.

Electron devices such as semiconductor devices are manufactured throughthe following steps: a step where the function/performance design of adevice is performed; a step where a reticle based on the design step ismanufactured; a step where a wafer is manufactured using a siliconmaterial; a lithography step where a pattern of a mask (the reticle) istransferred onto the wafer with the exposure apparatus (patternformation apparatus) of the embodiment described earlier and theexposure method thereof; a development step where the exposed wafer isdeveloped; an etching step where an exposed member of an area other thanan area where resist remains is removed by etching; a resist removingstep where the resist that is no longer necessary when the etching iscompleted is removed; a device assembly step (including a dicingprocess, a bonding process, and a packaging process); an inspectionstep; and the like. In this case, in the lithography step, the exposuremethod described earlier is executed using the exposure apparatus of theembodiment above L5 and device patterns are formed on the wafer, andtherefore, the devices with high integration degree can be manufacturedwith high productivity.

While the above-described embodiment of the present invention is thepresently preferred embodiment thereof, those skilled in the art oflithography systems will readily recognize that numerous additions,modifications, and substitutions may be made to the above-describedembodiment without departing from the spirit and scope thereof. It isintended that all such modifications, additions, and substitutions fallwithin the scope of the present invention, which is best defined by theclaims appended below.

1. An exposure apparatus that exposes an object with an energy beam viaan optical system supported by a first support member, the apparatuscomprising: a movable body that holds the object and is movable along apredetermined two-dimensional plane; a guide surface forming member thatforms a guide surface used when the movable body moves along thetwo-dimensional plane; a first drive system that drives the movablebody; a second support member that is placed apart from the guidesurface forming member on a side opposite to the optical system, via theguide surface forming member, and is fixed to the first support member;and a measurement system which includes a first measurement member thatirradiates a measurement surface parallel to the two-dimensional planewith a measurement beam and receives light from the measurement surface,and which obtains positional information of the movable body at leastwithin the two-dimensional plane based on an output of the firstmeasurement member, the measurement surface being arranged at one of themovable body and the second support member and at least a part of thefirst measurement member being arranged et the other of the movable bodyand the second support member.
 2. The exposure apparatus according toclaim 1, wherein the second support member is a beam-like member placedparallel to the two-dimensional plane.
 3. The exposure apparatusaccording to claim 2, wherein the beam-like member has both ends in itslongitudinal direction that are fixed to the first support member in asuspended state.
 4. The exposure apparatus according to claim 1, whereina grating whose periodic direction is in a direction parallel to thetwo-dimensional plane is placed on the measurement surface, and thefirst measurement member includes an encoder head that irradiates thegrating with the measurement beam and receives diffraction light fromthe grating.
 5. The exposure apparatus according to claim 1, wherein theguide surface forming member is a surface plate that is placed on theoptical system side of the second support member so as to be opposed tothe movable body and that has the guide surface parallel to thetwo-dimensional plane formed on one surface thereof on a side opposed tothe movable body.
 6. The exposure apparatus according to claim 5,wherein, the surface plate has a light-transmitting section throughwhich the measurement beam can pass.
 7. The exposure apparatus accordingto claim 5, wherein the first drive system includes a planar motor thathas a mover arranged at the movable body and a stator arranged at thesurface plate and drives the movable body by a drive force generatedbetween the stator and the mover.
 8. The exposure apparatus according toclaim 7, further comprising: a base member that supports the surfaceplate such that the surface plate is movable within a plane parallel tothe two-dimensional plane.
 9. The exposure apparatus according to claim8, further comprising: a surface plate driving system that includes astator arranged at the base member and a mover arranged at the surfaceplate and drives the surface plate with respect to the base member by adrive force generated between the mover and the stator.
 10. The exposureapparatus according to claim 1, wherein the measurement surface isarranged at the movable body, and the at least a part of the firstmeasurement member is placed at the second support member.
 11. Theexposure apparatus according to claim 10, wherein the movable body has afirst surface opposed to the optical system and parallel to thetwo-dimensional plane, on which the object is mounted and a secondsurface on a side opposite to the first surface and parallel to thetwo-dimensional plane, on which the measurement surface is placed. 12.The exposure apparatus according to claim 10, wherein the movable bodyincludes a first movable member that is driven by the first drive systemand a second movable member that holds the object and is supported bythe first movable member so as to be movable relative to the firstmovable member, and the measurement surface is placed at the secondmovable member.
 13. The exposure apparatus according to claim 12,further comprising: a second drive system that drives the second movablemember with respect to the first movable member in directions of sixdegrees of freedom that include a first axis direction and a second axisdirection orthogonal to each other within the two-dimensional plane. 14.The exposure apparatus according to claim 10, wherein the measurementsystem has one, or two or more of the first measurement members whosemeasurement center, which a substantial measurement axis passes throughon the measurement surface, coincides with an exposure position that isa center of an irradiation area of an energy beam irradiated on theobject.
 15. The exposure apparatus according to claim 10, furthercomprising: a mark detecting system that detects a mark placed on theobject, wherein the measurement system has one, or two or more secondmeasurement members whose measurement center, which a substantialmeasurement axis passes through on the measurement surface, coincideswith a detection center of the mark detecting system.
 16. The exposureapparatus according to claim 1, wherein the movable body is driven inthe directions of six degrees of freedom by the first drive system. 17.The exposure apparatus according to claim 1, wherein the measurementsystem is capable of further obtaining positional information of themovable body in a direction orthogonal to the two-dimensional plane. 18.The exposure apparatus according to claim 17, wherein the measurementsystem obtains the positional information of the movable body in thedirection orthogonal to the two-dimensional plane, at least at threenoncollinear positions.
 19. The exposure apparatus according to claim 1,further comprising: a control system that controls a position of themovable body via the first drive system, using measurement informationobtained by the measurement system.
 20. A device manufacturing method,comprising: exposing an object using the exposure apparatus according toclaim 1; and developing the exposed object.
 21. An exposure apparatusthat exposes an object with an energy beam via an optical systemsupported by a first support member, the apparatus comprising: a movablebody that holds the object and is movable along a predeterminedtwo-dimensional plane; a second support member fixed to the firstsupport member; a first drive system that drives the movable body; amovable body supporting member placed between the optical system and thesecond support member so as to be apart from the second support member,which supports the movable body at least at two points of the movablebody in a direction orthogonal to a longitudinal direction of the secondsupport member when the movable body moves along the two-dimensionalplane; and a measurement system which includes a first measurementmember that irradiates a measurement surface parallel to thetwo-dimensional plane with a measurement beam and receives light fromthe measurement surface, and which obtains positional information of themovable body at least within the two-dimensional plane based on anoutput of the first measurement member, the measurement surface beingarranged at one of the movable body and the second support member and atleast a part of the first measurement member being arranged at the otherof the movable body and the second support member.
 22. The exposureapparatus according to claim 21, wherein the movable body supportingmember is a surface plate that is placed on the optical system side ofthe second support member so as to be opposed to the movable body andthat has a guide surface parallel to the two-dimensional plane formed onone surface thereof on a side opposed to the movable body.
 23. Theexposure apparatus according to claim 21, further comprising: a controlsystem that controls a position of the movable body via the first drivesystem, using measurement information obtained by the measurementsystem.
 24. A device manufacturing method, comprising: exposing anobject using the exposure apparatus according to claim 21; anddeveloping the exposed object.